First Edition, 2012

ISBN 978-81-323-4632-6

© All rights reserved.

Published by: The English Press 4735/22 Prakashdeep Bldg, Ansari Road, Darya Ganj, Delhi - 110002 Email: [email protected] Table of Contents

Chapter 1 - Windows

Chapter 2 - Windows 1.0 and Windows 2.0

Chapter 3 - Windows 3.0

Chapter 4 - Windows 3.1x

Chapter 5 - Windows 95

Chapter 6 -

Chapter 7 - Windows Me

Chapter 8 - Windows NT

Chapter 9 - Windows CE

Chapter 10 - Windows 9x

Chapter 11 - Windows XP

Chapter 12 - Windows 7

Chapter- 1

Microsoft Windows

The latest Windows release, Windows 7, showing the desktop and

Company / developer Microsoft

Programmed in C, C++ and Assembly language

OS family Windows 9x, Windows CE and Windows NT Working state Publicly released

Source model Closed source / Shared source

Initial release November 20, 1985 (as Windows 1.0)

Windows 7, Windows 2008 R2 Latest stable release NT 6.1 Build 7600 (7600.16385.090713-1255)

(October 22, 2009; 14 months ago) [+/−]

Windows 7, Windows Server 2008 R2 Service Pack 1 RC Latest unstable release NT 6.1 Build 7601 (7601.17105.100929-1730)

(September 29, 2010; 2 months ago) [+/−]

Marketing target Personal computing

Available language(s) Multilingual

Update method

Supported platforms IA-32, -64 and

Kernel type Hybrid

Default Graphical (Windows Explorer)

License Proprietary commercial software

Microsoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. Microsoft first introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Microsoft Windows came to dominate the world's personal market, overtaking Mac OS, which had been introduced in 1984. As of October 2009, Windows had approximately 91% of the market share of the client operating systems for usage on the Internet. The most recent client version of Windows is Windows 7; the most recent server version is Windows Server 2008 R2; the most recent mobile OS version is Windows Phone 7.

Usage share Net Market Source W3Counter W3Schools StatOwl Global Stats Share November November November November November Date 2010 2010 2010 2010 2010 All versions 90.6% 80.37% 86.3% 87.33% 91.99% Windows XP 57.88% 42.49% 47% 43.8% 51.77% Windows 7 19.69% 22.28% 28.5% 21.97% 24.12% Windows Vista 12.62% 14.4% 9.5% 19.75% 16.1% Windows — 0.98% 1.1% 1.53% — Server 2003 0.34% 0.22% 0.2% 0.28% — Windows 98 0.05% — — — — Windows Me 0.02% — — — —

Security

Consumer versions of Windows were originally designed for ease-of-use on a single-user PC without a network connection, and did not have security features built in from the outset. However, Windows NT and its successors are designed for security (including on a network) and multi-user PCs, but were not initially designed with Internet security in mind as much, since, when it was first developed in the early 1990s, Internet use was less prevalent.

These design issues combined with programming errors (e.g. buffer overflows) and the popularity of Windows means that it is a frequent target of computer worm and virus writers. In June 2005, Bruce Schneier’s Counterpane Internet Security reported that it had seen over 1,000 new viruses and worms in the previous six months. In 2005, Kaspersky Lab found around 11,000 malicious programs—viruses, Trojans, back-doors, and exploits written for Windows.

Microsoft releases security patches through its Windows Update service approximately once a month (usually the second Tuesday of the month), although critical updates are made available at shorter intervals when necessary. In versions of Windows after and including Windows 2000 SP3 and Windows XP, updates can be automatically downloaded and installed if the user selects to do so. As a result, Service Pack 2 for Windows XP, as well as Service Pack 1 for Windows Server 2003, were installed by users more quickly than it otherwise might have been.

While the Windows 9x series offered the option of having profiles for multiple users, they had no concept of access privileges, and did not allow concurrent access; and so were not true multi-user operating systems. In addition, they implemented only partial . They were accordingly widely criticised for lack of security.

The Windows NT series of operating systems, by contrast, are true multi-user, and implement absolute memory protection. However, a lot of the advantages of being a true multi-user were nullified by the fact that, prior to Windows Vista, the first user account created during the setup was an administrator account, which was also the default for new accounts. Though Windows XP did have limited accounts, the majority of home users did not change to an account type with fewer rights – partially due to the number of programs which unnecessarily required administrator rights – and so most home users ran as administrator all the time.

Windows Vista changes this by introducing a privilege elevation system called . When logging in as a standard user, a logon session is created and a token containing only the most basic privileges is assigned. In this way, the new logon session is incapable of making changes that would affect the entire system. When logging in as a user in the Administrators group, two separate tokens are assigned. The first token contains all privileges typically awarded to an administrator, and the second is a restricted token similar to what a standard user would receive. User applications, including the Windows , are then started with the restricted token, resulting in a reduced privilege environment even under an Administrator account. When an application requests higher privileges or "Run as administrator" is clicked, UAC will prompt for confirmation and, if consent is given (including administrator credentials if the account requesting the elevation is not a member of the administrators group), start the process using the unrestricted token.

File permissions

All Windows versions from Windows NT 3 have been based on a permission system referred to as AGLP (Accounts, Global, Local, Permissions) AGDLP which in essence where file permissions are applied to the file/folder in the form of a 'local group' which then has other 'global groups' as members. These global groups then hold other groups or users depending on different Windows versions used. This system varies from other vendor products such as Linux and NetWare due to the 'static' allocation of permission being applied directory to the file or folder. However using this process of AGLP/AGDLP/AGUDLP allows a small number of static permissions to be applied and allows for easy changes to the account groups without reapplying the file permissions on the files and folders.

Windows Defender

On January 6, 2005, Microsoft released a Beta version of Microsoft AntiSpyware, based upon the previously released Giant AntiSpyware. On February 14, 2006, Microsoft AntiSpyware became Windows Defender with the release of Beta 2. Windows Defender is a freeware program designed to protect against spyware and other unwanted software. Windows XP and Windows Server 2003 users who have genuine copies of Microsoft Windows can freely download the program from Microsoft's web site, and Windows Defender ships as part of Windows Vista and 7.

Third-party analysis

In an article based on a report by Symantec, internetnews.com has described Microsoft Windows as having the "fewest number of patches and the shortest average patch development time of the five operating systems it monitored in the last six months of 2006." A study conducted by Kevin Mitnick and marketing communications firm Avantgarde in 2004 found that an unprotected and unpatched Windows XP system with Service Pack 1 lasted only 4 minutes on the Internet before it was compromised, and an unprotected and also unpatched Windows Server 2003 system was compromised after being connected to the internet for 8 hours. However, it is important to note that this study does not apply to Windows XP systems running the Service Pack 2 update (released in late 2004), which vastly improved the security of Windows XP. The computer that was running Windows XP Service Pack 2 was not compromised. The AOL National Cyber Security Alliance Online Safety Study of October 2004 determined that 80% of Windows users were infected by at least one spyware/adware product. Much documentation is available describing how to increase the security of Microsoft Windows products. Typical suggestions include deploying Microsoft Windows behind a hardware or software firewall, running anti-virus and anti-spyware software, and installing patches as they become available through Windows Update.

Emulation software

Emulation allows the use of some Windows applications without using Microsoft Windows. These include:

• — a free and open source software implementation of the Windows API, allowing one to run many Windows applications on x86-based platforms, including Linux and Mac OS X. Wine developers refer to it as a ""; and make use of Windows-style to emulate the Windows environment. o CrossOver — A Wine package with licensed fonts. Its developers are regular contributors to Wine, and focus on Wine running officially supported applications. o — TransGaming Technologies' proprietary fork of Wine, designed specifically for running games written for Microsoft Windows under Linux. A version of Cedega known as Cider is used by some video game publishers to allow Windows games to run on Mac OS X. Since wine was licensed under the LGPL Cedega has been unable to port the improvements made to wine to their proprietary codebase. o Darwine — A bundling of Wine to the PowerPC Macs running OS X by running wine on top of QEMU. Macs use the same Wine as other *NIX x86 systems. • ReactOS — An open-source OS that is intended to run the same software as Windows, originally designed to simulate Windows NT 4.0, now aiming at Windows XP and Vista/7 compatibility. It has been in the development stage since 1996. Chapter- 2 Windows 1.0 and Windows 2.0

Windows 1.0

Windows 1.0

Part of the Microsoft Windows family

Screenshot of Windows 1.01

Developer

Microsoft

Releases

Release date 20 November 1985

Current version 1.04 (April 1987; 23 years ago) Source model Closed source

License MS-EULA

Support status

Unsupported as of 31 December 2001

Windows 1.0 is a 16-bit graphical operating environment that was released on 20 November 1985. It was Microsoft's first attempt to implement a multi-tasking -based operating environment on the PC platform. Windows 1.0 was the first version of Windows launched. It was succeeded by Windows 2.0.

History

Version 1.02, released in May 1986, was international and had editions in several European languages. Version 1.03, released in August 1986, was for the US- and international market, with enhancements making it consistent with the international release. It included drivers for European keyboards and additional screen and printer drivers. Version 1.04, released in April 1987, added support for the VGA graphics adapters of the new IBM PS/2 . At the same time, Microsoft and IBM announced the introduction of OS/2 and its graphical OS/2 Presentation Manager, which were supposed to ultimately replace both MS-DOS and Windows.

Windows 1.0 was superseded by Windows 2.0 in November 1987, but supported by Microsoft for sixteen years, until 31 December 2001.

Competition

The history of Windows dates back to September 1981, when the project named "Interface Manager" was started. It was first presented to the public on 10 November 1983, renamed to "Microsoft Windows"; the two years of delay before release led to charges that it was "vaporware". The initially announced version of Windows had features so much resembling the Macintosh interface that Microsoft had to change many of them: overlapping windows, although supported by the GUI engine, weren't allowed for exactly this reason. The announcement of Windows' imminent arrival in 1985 probably did not help the sales of VisiCorp's VisiOn environment which debuted at the same time. However, even when finally released, Windows 1.0 aroused little interest.

Another GUI for the PC platform at the time was GEM. It used more aspects from the Macintosh GUI, for example the trash can concept (which Microsoft would later employ in future Windows releases) and more generally the desktop interaction. GEM was eventually used as the standard GUI for the Atari's ST range of 68k-based computers, which were sometimes referred to as Jackintoshes (the company being run by Jack Tramiel). GEM was also included in the Amstrad PC1512, probably the first 8086 based PC targeted at the home consumer and sold alongside TV's and washing machines at appliance stores. GEM's resemblance to the Mac OS later caused legal trouble for the manufacturer, Digital Research, who was obliged to seriously cripple the desktop's appearance and functionality (applications were not affected).

GEM was relying on multitasking of the OS under it (non-existing in DOS on that time), so users had to close one program in order to run another one. Collections of related programs, like GEM Draw, had confusing File menu items like Close (to Edit) to facilitate switching.

An alternative multitasker released shortly before was DESQview, a successor of IBM's failed TopView from 1984. It did not have graphical capabilities initially, but is able to multitask DOS applications in windows as long as they are well-behaved or have a specially written "loader" to fix them on the fly.

Windows 1.0 market share grew very slowly. Early Windows versions of Microsoft Excel and other Windows applications were bundled with a runtime version of Windows, presumably to both increase sales of the applications and allow users to "test drive" Windows at no additional cost.

The Macintosh remained the platform of choice especially for high-end graphics and desktop publishing (DTP). Although Aldus PageMaker shipped in January 1987 with a Windows executable, it remained a curiosity due to poor support relative to the Mac version, and a steep $795 price tag.

Other shell programs for MS-DOS include Norton Commander, PC Tools, XTree. DOS Shell, and DOS Menu (in MS-DOS version 4.0). These applications attempted to be organizational and menu-driven tools, and did not try at all to be a 'desktop' shell.

Features

Windows 1.0 offers limited multitasking of existing MS-DOS programs and concentrates on creating an interaction paradigm (cf. message loop), an execution model and a stable API for native programs for the future. Due to Microsoft's extensive support for backward compatibility, it is not only possible to execute Windows 1.0 binary programs on current versions of Windows to a large extent, but also to recompile their source code into an equally functional "modern" application with just limited modifications.

Windows 1.0 is often regarded as a "front-end to the MS-DOS operating system", a description which has also been applied to subsequent versions of Windows. Windows 1.0 is an MS-DOS program. Windows 1.0 programs can call MS-DOS functions, and GUI programs are run from .exe files just like MS-DOS programs. However, Windows .exe files had their own "new executable" (NE) file format, which only Windows could process and which, for example, allowed demand-loading of code and data. Applications were supposed to handle memory only through Windows' own system, which implemented a software-based scheme allowing for applications larger than available RAM. Because graphics support in MS-DOS is extremely limited, MS-DOS applications have to go to the bare hardware (or sometimes just to the BIOS) to get work done. Therefore, Windows 1.0 included original device drivers for video cards, a mouse, keyboards, printers and serial communications, and applications were supposed to only invoke APIs built upon these drivers. However, this extended to other APIs such as file system management functions. In this sense, Windows 1.0 was designed to be extended into a full-fledged operating system, rather than being just a graphics environment used by applications. Indeed, Windows 1.0 is a "DOS front-end" and cannot operate without a DOS environment (it uses, for example, the file-handling functions provided by DOS.) The level of replacement increases in subsequent versions.

The system requirements for Windows 1.01 constituted CGA/Hercules/EGA (listed as "Monochrome or color monitor"), MS-DOS 2.0, 256 kB of memory or greater, and two double-sided disk drives or a hard drive.

Windows 1.0 runs a shell program known as MS-DOS Executive. Other supplied programs are Calculator, , , Clipboard viewer, Clock, , Notepad, Paint, Reversi, Terminal, and Write.

Windows 1.0 does not allow overlapping windows. Instead all windows are tiled. Only dialog boxes can appear over other windows.

Windows 1.0 executables, while having the same .exe extension and initial file header as MS-DOS programs, do not contain the so-called MS-DOS stub which prints the "This program requires Microsoft Windows" message and exits when the program is run outside of Windows. Instead, the file header was formatted in such a way as to make DOS reject the executable with a "program too large to fit in memory" error message.

From the beginning, Windows was intended to multitask programs (although this originally only applied to native applications and for many versions the multitasking was co-operative, rather than preemptive).

Pre-release versions had menus at the bottom of windows, as it was used in Microsoft applications, such as Word and Multiplan of that era; however, this was changed before the first release.

Windows 2.0

Windows 2.0

Part of the Microsoft Windows family

Screenshot of Windows 2.0

Developer

Microsoft

Releases

Release date November 1987

Current version 2.03 (November 1987; 23 years ago)

Source model Closed source

License MS-EULA

Support status

Unsupported as of December 31st 2001 Windows 2.0 is a 16-bit Microsoft Windows graphical user interface-based operating environment that was released in November 1987 and superseded Windows 1.0. With Windows 2.1x in 1988, Windows 2.0 was supplemented by Windows/286 and Windows/386. Windows 2.0, Windows/286 and Windows/386 were superseded by Windows 3.0 in May 1990, but supported by Microsoft for fourteen years, until 31 December 2001.

History

Application support

The first Windows versions of Microsoft Word and Microsoft Excel ran on Windows 2.0. Third-party developer support for Windows increased substantially with this version (some shipped the software with their applications, for customers who had not purchased the full version of Windows). However, most developers still maintained DOS versions of their applications, as Windows users were still a distinct minority of their market.

Applications shipping with Windows 2.0:

• CALC.EXE • CALENDAR.EXE • CARDFILE.EXE • CLIPBRD.EXE • CLOCK.EXE • CONTROL.EXE • CVTPAINT.EXE • MSDOS.EXE • MSDOSD.EXE • NOTEPAD.EXE • PAINT.EXE • REVERSI.EXE • TERMINAL.EXE • WRITE.EXE

Legal conflict with Apple

On 17 March 1988, Apple filed suit against Microsoft and Hewlett-Packard, accusing them of violating copyrights Apple held on the Macintosh System Software. Apple claimed the "look and feel" of the Macintosh operating system, taken as a whole, was protected by copyright and that Windows 2.0 violated this copyright by having the same icons. Features

Windows 2.0 allowed application windows to overlap each other unlike its predecessor Windows 1.0, which could display only tiled windows. Windows 2.0 also introduced more sophisticated keyboard-shortcuts and the terminology of "Minimize" and "Maximize", as opposed to "Iconize" and "Zoom" in Windows 1.0. Chapter- 3 Windows 3.0

Windows 3.0

Part of the Microsoft Windows family

Screenshot of Windows 3.0

Developer

Microsoft

Releases

Release date 22 May 1990

3.00a Current version Multimedia Extensions (October 20, 1991; 19 years ago)

Source model Closed source

License MS-EULA

Support status

Unsupported as of 31 December 2001

Windows 3.0 is the third major release of Microsoft Windows, and was released on 22 May 1990. It became the first widely successful version of Windows and a rival to Apple Macintosh and the Commodore Amiga on the GUI front. It was followed by Windows 3.1.

Features

Windows 3.0 succeeded Windows 2.1x and included a significantly revamped user interface as well as technical improvements to make better use of the memory management capabilities of Intel's 80286 and 80386 processors. Text-mode programs written for MS-DOS could be run within a window (a feature previously available in a more limited form with Windows/386 2.1), making the system usable as a crude multitasking base for legacy programs. However, this was of limited use for the home market, where most games and entertainment programs continued to require raw DOS access.

The MS-DOS Executive /program launcher was replaced with the icon-based and the list-based File Manager, thereby simplifying the launching of applications. The MS-DOS Executive is also included as an alternative to these. The Control Panel, previously available as a standard-looking applet, was re-modeled after the one in Mac OS. It centralized system settings, including limited control over the color scheme of the interface.

A number of simple applications were included, such as the text editor Notepad and the word Write (both inherited from earlier versions of Windows), a macro recorder (new; later dropped), the paint program Paintbrush (inherited but substantially improved), and a calculator (also inherited). Also, the earlier Reversi game was complemented with the card game Solitaire.

The Windows icons and graphics were redesigned to take advantage of VGA's 16-color mode. Earlier versions only supported eight colors though could run on monochrome video adapters. Windows 3.0 also allowed the user to use a 256 color video adapter, whereas previous versions only supported 16 colors.

Windows 3.0 includes a Protected/Enhanced mode which allows Windows applications to use more memory in a more painless manner than their DOS counterparts could. It can run in any of Real, Standard, or 386 Enhanced modes, and is compatible with any Intel processor from the 8086/8088 up to 80286 and 80386. Windows 3.0 tries to auto detect which mode to run in, although it can be forced to run in a specific mode using the : /r (real mode), /s ("standard" 286 protected mode) and /3 (386 enhanced protected mode) respectively. This was the first version to run Windows programs in protected mode, although the 386 enhanced mode kernel was an enhanced version of the protected mode kernel in Windows/386.

Due to this backward compatibility, Windows 3.0 applications also must be compiled in a 16-bit environment, without ever using the full 32-bit capabilities of the 386 CPU.

A "multimedia" version, Windows 3.0 with Multimedia Extensions 1.0, was released later in 1991. This was bundled with "multimedia upgrade kits", comprising a CD-ROM drive and a sound card, such as the Creative Labs Sound Blaster Pro. This version was the precursor to the multimedia features available in Windows 3.1 and later, and was part of Microsoft's specification for the Multimedia PC.

Windows 3.0 was the last version of Windows to advertise 100% compatibility with older Windows applications. This only applies to real mode.

A boxed copy of Windows 3.0 in the original shrinkwrap. This boxed copy includes 3.5" floppies (720K version) for DOS systems.

System requirements

The official system requirements for Windows 3.0:

• 8086/8088 processor or better • 640K conventional memory, though 1 MB of extended memory recommended. • Hard disk with 6-7MB of free space • CGA/EGA/VGA/Hercules/8514/A graphics and an appropriate and compatible monitor Also, a Microsoft-compatible mouse is recommended.

Memory modes

Windows 3.0 was the only version of Windows that could be run in three different memory modes:

• Real mode, intended for older computers with a CPU below Intel 80286, and corresponding to its real mode; • Standard mode, intended for computers with an 80286 processor, and corresponding to its protected mode; • 386 Enhanced mode, intended for newer computers with an Intel 80386 processor or above, and corresponding to its protected mode and virtual 8086 mode.

Real mode primarily existed as a way to run Windows 2.x applications. It was removed in Windows 3.1x. Almost all applications designed for Windows 3.0 had to be run in Standard or 386 Enhanced modes. However, it was necessary to load Windows 3.0 in Real mode to run SWAPFILE.EXE, which allowed users to change virtual memory settings.

Standard mode was used most often as its requirements were more in-line with an average PC of that era – a 286 processor with at least 1 MB of memory. Incidentally, not all 286 and 386 computers remapped memory between 640 KB (the upper limit of Conventional memory) and 1 MB as extended memory — some did not show memory between 640 KB and 1 MB at all — so on some systems with 1 MB of RAM, there is no extended memory and memory was limited to 640 KB. On such a system, Windows was limited to real mode. Many 386 computers ran Windows 3.0 in Standard mode due to a lack of memory.

386 Enhanced mode implemented all the benefits of Standard mode, plus 32-bit addressing and paging for faster memory access, and virtual 8086 mode for safer execution of MS-DOS programs: each of them now ran in a virtual machine. In the previous modes, multiple MS-DOS programs could only be run in full-screen, and only the program currently active was executing; but in 386 enhanced mode, they could be run simultaneously in separate windows. This mode required a 386 processor and 1 MB of extended memory (in addition to the base 640KB) – beyond the specifications of most PCs sold in 1990.

Multimedia Extensions

The Multimedia Extensions were released in autumn 1991 to support sound cards, as well as CD-ROM drives, which were then becoming increasingly available. The Multimedia Extensions were released to Original Equipment Manufacturers (OEMs), mainly CD- ROM drive and sound card manufacturers, and added basic multimedia support for audio input and output and a CD audio player application to Windows 3.0. The Multimedia Extensions' new features were not available in Windows 3.0 real mode. Windows 3.1x would later incorporate many of its features. Microsoft developed the Windows Sound System sound card specification to complement these extensions.

The MME API was the first universal and standardized Windows audio API. Wave sound events played in Windows (up to Windows XP) and MIDI I/O use MME. The devices listed in the Multimedia/Sounds and Audio control panel applet represent the MME API of the sound card driver.

MME lacks channel mixing, so only one audio stream can be rendered at a time. MME supports sharing the audio device for playback between multiple applications starting with Windows 2000, up to two channels of recording, 16-bit audio bit depth and sampling rates of up to 44.1 kHz with all the audio being mixed and sampled to 44.1 kHz.

Marketing

This version of Windows was the first to be pre-installed on hard drives by PC- compatible manufacturers. Zenith Data Systems had previously shipped all of its computers with Windows 1.0 or later 2.x on diskettes but committed early in the development of Windows 3.0 to shipping it pre-installed. Indeed, the Zenith division had pushed Microsoft hard to develop the graphical user interface because of Zenith's direct competition with Apple in the college and university market.

Windows 3.0 was not available as a run-time version, as was the case with its predecessors. A limited-use version of Windows 2.x was often bundled with other applications (i.e. Ami Pro) due to the low market penetration of Windows itself. It again was unsupported after December 31, 2001. Chapter- 4 Windows 3.1x

Windows 3.1x

Part of the Microsoft Windows family

Screenshot of Windows 3.11

Developer

Microsoft

Releases

Release date 6 April 1992

Current version 3.11 (December 31, 1993; 16 years ago)

Source model Closed source

License MS-EULA

Support status

Unsupported as of 31 December 2001

Windows 3.1x is a series of 16-bit operating systems produced by Microsoft for use on personal computers. The series began with Windows 3.1, which was first sold during March 1992 as a successor to Windows 3.0. Further editions were released between 1992 and 1994 until the series was superseded by Windows 95.

Editions

Windows 3.1 start up screen

Windows 3.1 showing some of the personalisation options available

Windows 3.2 was first released in Simplified Chinese

Base version

Windows 3.1 (originally codenamed Janus, of which two betas were published), released in April 1992, includes a TrueType font system (and a set of highly legible fonts already installed), which effectively made Windows a serious desktop publishing platform for the first time. Similar functionality was available for Windows 3.0 through the Adobe Type Manager (ATM) font system from Adobe.

Windows 3.1 was designed to have backward compatibility with older Windows platforms. As with Windows 3.0, version 3.1 had File Manager and Program Manager, but unlike all previous versions, Windows 3.1 and later support 32-bit disk access, cannot run in real mode, and included Minesweeper instead of Reversi (though Reversi was included in some copies).

Windows 3.1 Multimedia PC Version (Beta only, released Nov 1992 — codenamed Bombay) Included a media viewer, and the ability to play video files. It was targeted to the new multi-media PC and included sound and video integration with CD-ROM support. Versions with special font support

A special version named Windows 3.1 for Central and Eastern Europe was released that allowed the use of Cyrillic and had fonts with diacritical marks characteristic of Central and Eastern European languages. Microsoft introduced its own codepage (Windows- 1250) and supported its use in violation of many countries' ISO standards (e.g., the official Polish codepage is ISO-8859-2, which was ignored by Microsoft but is supported by contemporary versions). Similarly, Microsoft also released Windows 3.1J with support for the Japanese language, which shipped 1.46 million copies in its first year on the market (1993) in Japan.

Windows 3.11

On 31 December 1993, Microsoft released an update for Windows 3.1 known as Windows 3.11. Thus, Windows 3.11 is not a standalone version of Windows, but rather a software update from Windows 3.1, much like modern packs. For those who did not own Windows 3.1, full disk sets of Windows 3.11 were available at the time.

Modular Windows

Modular Windows is a special version of Windows 3.1, designed to run on the Tandy Video Information System.

Windows 3.2

In 1994, Microsoft released a Simplified Chinese version of Windows for the Chinese market. The updated system identified itself as Windows 3.2. Thus, Windows 3.2 is the Chinese version of Windows 3.11. The update was limited to this language version, as it fixed only issues related to the complex writing system of the Chinese language.

Windows 3.2 was generally sold by computer manufacturers with a ten-disk version of MS-DOS that also had Simplified Chinese characters in basic output and some translated utilities. Windows for Workgroups

Advanced network capabilities of Windows for Workgroups 3.11

Windows for Workgroups is an extension that allowed users to share their resources and to request those of others without a centralized authentication server. It used the SMB protocol over NetBIOS.

Windows for Workgroups 3.1

Windows for Workgroups 3.1 (originally codenamed Winball and later Sparta), released in October 1992, features native networking support. Windows for Workgroups 3.1 is an extended version of Windows 3.1 that comes with SMB file sharing support via the NetBIOS based NBF and/or IPX network transport protocols, includes the Hearts card game, and introduced VSHARE.386, the Virtual version of the SHARE.EXE Terminate and Stay Resident program.

Windows for Workgroups 3.11

Windows for Workgroups 3.11 (originally codenamed Snowball) was released on 11 August 1993, and shipped in November 1993. It supported 32-bit file access, full 32-bit network redirectors, and the VCACHE.386 file , shared between them. The standard execution mode of the Windows kernel was discontinued in Windows for Workgroups 3.11.

A Winsock package was required to support TCP/IP networking in Windows 3.x. Usually third-party packages were used, but in August 1994 Microsoft released an add-on package (codenamed Wolverine) that provided limited TCP/IP support in Windows for Workgroups 3.11. Wolverine was a 32-bit stack (accessible from 16-bit Windows application via WinSock thunks), which gave it superior performance to most of the third-party TCP/IP Windows stacks available. However, it was only compatible with Windows for Workgroups 3.11, and lacked support for dial-up. The Wolverine stack was an early version of the TCP/IP stack that would later ship with Windows 95, and provided an early testbed for the 16-to-32-bit compatibility layer that was crucial to Windows 95's success.

Add-ons

Video for Windows

Video for Windows was first introduced in November 1992 as a reaction to Apple Computer's QuickTime technology which added digital video to the Macintosh platform. Costing around $200, the software included editing and encoding programs for use with video input boards. A runtime version for viewing videos only was also made available. Originally released as a free add-on to Windows 3.1 and Windows 3.11, it then became an integral component of Windows 95 and later. Like QuickTime there were three components in Video for Windows. The technology introduced a file format designed to store digital video, Audio Video Interleave (AVI). The technology provided an application programming interface that allowed software developers working on the Windows platform to add the ability to play or manipulate digital video to their own applications. Lastly, it included a suite of software for playing and manipulating digital video.

Windows for

Windows for Pen Computing was a series of Microsoft-produced add-ons for Microsoft Windows versions in the mid-1990s with additional tools for tablet PCs. Windows for Pen Computing (also known as Pen Windows and W4PC) was developed as Microsoft's Pen computing response to the PenPoint OS by GO Corporation. Windows for Pen Computing was rendered obsolete by the Tablet PC support for Windows XP Tablet PC Edition in 2002.

Win32s

Windows 3.1x was given limited compatibility with the then-new 32-bit Windows API used by Windows NT by another add-on package, Win32s. There was rumor that Microsoft didn't want to increment any mainstream Windows 3.1x version to something like "Windows 3.2" because it could be confused with the Win32 API or otherwise distract consumers from upgrading to a "real 32-bit OS" like the then-upcoming Windows 95 was, though Windows NT 3.1 and 3.5 were 32-bit OSes that looked similar in appearance. For testing of the new Win32s functions the game freecell was included.

Applications

Windows 3.1x introduced new possibilities for applications, especially multimedia applications. During this era, Microsoft developed a new range of software that was implemented on this operating environment, called Microsoft Home, Microsoft Bob being one of the programs.

Program Manager

Program Manager was included in all versions of Windows from version 3.0 until Windows XP Service Pack 1. A non-operable icon library named progman.exe is included in Windows XP Service Pack 2, and the file was removed entirely from Windows Vista.

If Program Manager is started under Windows XP Service Pack 2 and later, it does not appear to run, but when a .grp file created for Windows 3.1 is processed, it converts the .grp file contents to a Start Menu folder.

Internet Explorer

Microsoft released versions of Internet Explorer from 2.0 up to the first release of version 5.0 for Windows 3.1.

Promotion and reception

Microsoft began a television advertising campaign for the first time on 1 March 1992. The advertisements, developed by Ogilvy & Mather, were designed to introduce a broader audience to Windows. Windows 3.1 was shipped worldwide on April 6, 1992, and reached three million sales two months later. The year of Windows 3.1's release was successful for Microsoft, who were named the "Most Innovative Company Operating in the U.S." by Forbes Magazine, while Windows became the most widely-used GUI-based operating environment.

Controversy

DR-DOS compatibility

The installer to the beta release used code that checked whether it was running on Microsoft-licensed DOS or another DOS operating system (such as DR-DOS). The code ran several functional tests that succeeded on MS-DOS and IBM PC DOS, but resulted in a technical support message on competing operating systems. If the system was not MS- DOS, the installer would fail. Digital Research, who owned DR-DOS, released a patch within weeks to allow the installer to continue. Microsoft disabled, but did not remove, this warning message for the final release of Windows 3.1. When Caldera Systems bought DR-DOS from Novell, they brought a lawsuit against Microsoft over the AARD code, which was later settled.

Legacy

Windows 3.x was superseded by the release of Windows 95 in August 1995.

Windows 3.1 found a niche market as an embedded operating system after becoming obsolete in the PC world. Up until November 2008, both Virgin Atlantic and Qantas employed it for some of the onboard entertainment systems on long-distance jets. It also sees continued use as an embedded OS in retail cash tills.

On 9 July 2008, it was announced that Windows for Workgroups 3.11 for the embedded devices channel would no longer be made available for OEM distribution as of 1 November 2008.

Notes

Microsoft Knowledge Base

• Microsoft Windows for Workgroups Resource Kit • Microsoft. KB32905: Windows Version History • Microsoft. KB126746: Windows for Workgroups Version History • Microsoft. KB83210: Windows 3.1 Hardware Compatibility List Chapter- 5 Windows 95

Windows 95

Part of the Microsoft Windows family

Screenshot of Windows 95

Developer

Microsoft

Releases

Release date 24 August 1995

Current version 4.00 OEM Service Release 2.5 (OSR2.5) (Build 950) (4.00.950 C) (November 26, 1997; 13 years ago)

Source model Closed source

License Microsoft EULA

Kernel type Monolithic

Platform support IA-32

Support status

Unsupported as of 31 December 2001

Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products. During development it was referred to as Windows 4.0 or by the internal codename Chicago.

Windows 95 integrated Microsoft's formerly separate MS-DOS and Windows products. It featured significant improvements over its predecessor, Windows 3.1, most notably in the graphical user interface (GUI) and in its relatively simplified "plug-n-play" features. There were also major changes made at lower levels of the operating system, such as moving from a mainly 16-bit architecture to a pre-emptively multitasked 32-bit architecture.

In the marketplace, Windows 95 was a major success, and within a year or two of its release had become the most successful operating system ever produced. It also had the effect of driving other major players in the DOS-compatible operating system market out of business, something which would later be used in court against Microsoft. Some three years after its introduction, Windows 95 was succeeded by Windows 98.

Development

The initial design and planning of Windows 95 can be traced back to around March 1992, just after the release of Windows 3.1. At this time Windows for Workgroups 3.1 and Windows NT 3.1 were still in development and Microsoft's plan for the future was focused on Cairo. Cairo would be Microsoft's next-generation operating system based on Windows NT and featuring a new user interface and an object-based file system, but it was not planned to be shipped before 1994 (Cairo would eventually partially ship in July 1996 in the form Windows NT 4.0, without the object-based file system however, which would later evolve into WinFS).

Simultaneously with Windows 3.1's release, IBM started shipping OS/2 2.0. Microsoft realized they were in need of an updated version of Windows that could support 32-bit applications and preemptive multitasking, but could still run on low-end hardware (Windows NT did not.) So the development of Windows "Chicago" was started and, as it was planned for a late 1993 release, became known as Windows 93. Initially the decision was made not to include a new user interface, as this was planned for Cairo, and only focus on making installation, configuration, and networking easier. Windows 93 would ship together with MS-DOS 7.0 offering a more integrated experience to the user and making it pointless for other companies to create DOS clones. MS-DOS 7.0 was in development at that time under the code name "Jaguar" and could optionally run on top of a Windows 3.1-based 32-bit protected mode kernel called "Cougar" in order to better compete with DR-DOS.

Microsoft's product plan looked as follows:

Planned Codename Description Released as release date "Janus" March 1992 Windows 3.1 September Upgrade to MS-DOS 5.0, adding third party "Astro" MS-DOS 6.0 1992 tools to surpass DR-DOS 6.0 in features. Windows for "Winball" Workgroups 3.1 Next major release of real-mode MS-DOS, "Jaguar" June 1993 (MS-DOS 7.0) better integrating with Windows A 32-bit protected-mode MS-DOS kernel (Windows 95 "Cougar" June 1993 based on Windows' 386 enhanced-mode VMM) kernel The 32-bit Windows subsystem that could run on top of "Cougar" implementing a subset of "Panther" June 1993 Windows 95 Windows NT's Win32 API, but a superset of the Win32s API. Windows for Mobile Computing, based on "Rover" June 1993 "Panther" A new version of Windows build from the Windows NT NT ground up as an operating system for servers 3.1 and . "Cairo" "Sloturn"

The first version of Chicago's feature specification was finished on 30 September 1992. Cougar was to become Chicago's kernel.

Beta

Prior to the official release, the American public was given a chance to preview Windows 95 in the Windows 95 Preview Program. For US$19.95, users were sent a set of 3.5-inch floppy diskettes that would install Windows 95 either as an upgrade to Windows 3.1x or as a fresh install on a clean computer. Users who bought into the program were also given a free preview of The Microsoft Network (MSN), the online service that Microsoft launched with Windows 95. The preview versions expired in November 1995, after which the user would have to purchase their own copy of the final version of Windows 95.

Several Windows 95 betas were released before the final launch:

Build 58s introduced a Start menu prototype. It divided the functions of the Windows 95 Start menu up into three buttons. Future Chicago builds combined these three into the Start button still recognized today.

Build 58s included a new File Manager, Chicago Explorer, which remained relatively unchanged in the initial version of Windows 95 and in Build Windows NT 4.0. Build 58s still 58s included Program Manager as found in Windows 3.1, although this application was supplemented by the new desktop and /Start menu designs.

This build also introduced shortcuts (Chicago referred to them as Links) and native right click functionality, which Windows 3.1 lacked. It also introduced long file name support.

Build 73g is the next leaked build of Windows Chicago with a date stamp Build of November 1993. It is more of the 73g same thing as Build 58 with a few UI tweaks and a network logon box at startup.

Build 81 follows build 73g. The date stamp says it is from January 1994. The three start buttons are combined into one. However the 8 character folder limit makes the start menu item Build accessories spelt accees~1. Programs 81 running are only displayed on the taskbar. The briefcase UI was improved. The My Computer item is displayed when opened as: drives and Network as: network Build 122 was the first version of Build Chicago to call itself a Beta edition. 122 Again, there is not much info on this version, but there is a date stamp of June 9, 1994. Build 189 is the first version to call itself Windows 95. The date stamp is marked September 22, 1994. The UI has been completely re-done to where it looks and feels like the final version Build of Windows 95, though there still are 189 numerous things left over from Chicago. The start menu also slightly differs from newer builds of Windows 95, as there is actually color along the side. Build 224 is Windows 95 beta 2. Build Only a date stamp of November 8,

224 1994 can be found as information on this build.

Build 347 is the Windows 95 "Final Beta Release". The build number Build refers to a German release, but seems 347 to install in English. This version has a date stamp of March 17, 1995.

Build 468 is the May Test Release version of Windows 95, with a date Build stamp of May 11, 1995. This version 468 is so close to the final Windows 95, it can be mistaken for it. Build 480 is the May Test Release. It was released in two languages: Build English and German. According to 480 the build number, this is Release Candidate 1. Build Build is dated June 8, 1995. The build 490 number seems to indicate that this is (RC1) Release Candidate 1. Release

Microsoft Windows 95 operating system cover shot

Windows 95 was released with great fanfare, including a commercial featuring the Rolling Stones' 1981 single "Start Me Up" (a reference to the Start button). It was widely reported that Microsoft paid the Rolling Stones between US$8 and US$14 million for the use of the song in the 95 advertising campaign. According to sources at Microsoft, however, this was just a rumor spread by the Stones to increase their market value, and Microsoft actually paid a fraction of that amount. A 30-minute promotional video, labeled a "cyber sitcom", featuring Jennifer Aniston and Matthew Perry, was also released to showcase the features of Windows 95. Microsoft's US$300 million advertising campaign featured stories of waiting in line outside stores to get a copy.

In the UK, the largest computer chain PC World received a large number of oversized Windows 95 boxes, posters and point of sale material, and many branches opened at midnight to sell the first copies of the product, although these customers were far fewer in number than publicity had suggested. In London Microsoft gave free newspapers to people.

In the United States, the Empire State Building in New York City was lit to match the colors of the Windows logo. In Canada, a 328 ft (100 m) banner was hung from the top of the CN Tower in Toronto. Copies of The Times were available for free in the United Kingdom where Microsoft paid for 1.5 million issues (twice the daily circulation at the time).

The release included a number of "Fun Stuff" items on the CD, including music videos of Edie Brickell's "Good Times, Bad Times" and Weezer's "Buddy Holly".

Architecture

Architectural diagram

Windows 95 was designed to be maximally compatible with existing MS-DOS and 16-bit Windows applications and device drivers, while under this constraint offering a more stable and better performing system. Architecturally, Windows 95 can be considered an evolution of Windows for Workgroups' 386 enhanced mode. The lowest level of the operating system is formed by a large number of virtual device drivers (VxDs) running in 32-bit protected mode and one or more virtual DOS machines running in virtual 8086 mode. The virtual device drivers can be responsible for handling physical devices (such as video and network cards), emulating virtual devices used by the virtual machines, or providing various system services. The three most important virtual device drivers are:

Virtual Machine Manager The Virtual Machine Manager (VMM32.VXD) can be considered the kernel of Windows 95 and is responsible for tasks such as memory management, event and handling, loading and initialization of all other virtual device drivers, the creation of new virtual machines, and scheduling of threads. Configuration Manager The Configuration Manager (CONFIGMG) is responsible for implementing Plug and Play functionality. It detects all devices in the system using several enumerators, monitors the system for changes to the hardware configuration. It is responsible for assigning various resources (I/O ports, IRQs, DMA channels, and memory) to the devices in a conflict free fashion. Manager (Input/Output Subsystem) The Installable File System Manager coordinates the access to various file systems. Windows 95 ships with support for FAT16, and in later releases FAT32, file systems (VFAT), ISO 9660 (CDFS), and several network redirectors. A dynamically sized disk buffer is provided by VCACHE. In the Block I/O Subsystem, requests are scheduled by the Input/Output Supervisor. Access to the disk is performed by a port driver, or in the case of a SCSI device, by a miniport driver working atop the SCSI layer. Like Windows for Workgroups running with 32-bit file and disk access enabled, I/O operations can be handled entirely in 32-bit protected mode, bypassing MS- DOS and the BIOS, giving a significant performance improvement. In case there is no native Windows driver for a certain storage device, or if a device is forced to run in compatibility mode, the Real Mode Mapper port driver can access it through MS-DOS.

The Win32 API is implemented by three modules, each consisting of a 16-bit and a 32-bit component:

Kernel Kernel (KRNL386.EXE, KERNEL32.DLL, and VWIN32.VXD) provides high level access to functions such as memory and process management, and access to the file system. User User (USER.EXE and USER32.DLL) is responsible for managing and drawing the various user interface components, such as windows, menus, and buttons. GDI The Graphics Device Interface (GDI.EXE and GDI32.DLL) is responsible for drawing graphics in a device-independent way.

Dependence on MS-DOS

To end-users MS-DOS appeared as an underlying component of Windows 95. For example, it was possible to prevent loading the graphical user interface and boot the system into a real-mode MS-DOS environment. This sparked debate amongst users and professionals over the question of to what extent Windows 95 was an operating system or merely a graphical shell running on top of MS-DOS. From an architectural stance both viewpoints lack nuance.

When the graphical user interface was started, the virtual machine manager took over the filesystem-related and disk-related functionality from MS-DOS, which itself was demoted to a compatibility layer for 16-bit device drivers. This contrasted with earlier versions of Windows which relied on MS-DOS to perform file and disk access. (Windows for Workgroups 3.11 could also largely bypass MS-DOS when 32-bit file access and 32-bit disk access was enabled.) Keeping MS-DOS in memory allowed Windows 95 to use DOS device drivers if suitable Windows drivers were unavailable. MS-DOS also still handled most other functions (for example, allocating memory and parsing file names), issued by legacy Win16 and DOS applications, as Microsoft saw little benefit in replacing these helper functions with newly-written 32-bit code.

A negative consequence of keeping MS-DOS around was that Windows had to do some work to keep DOS's internal data structures synchronized with those of Windows itself. When starting an application, even a native 32-bit Windows application, MS-DOS would momentarily execute to create a data structure (the program segment prefix) and it was even theoretically possible for MS-DOS to run out of conventional memory while doing so, preventing the application from launching. Windows 3.x in fact allocated FIXED segments in conventional memory first, which obviously can conflict and since the segments was allocated as FIXED, Windows could not move them, which would prevent any more applications from launching. This was fixed in Windows 95.

User interface

Windows 95 first-run dialog, explaining use of the Start button The basic elements of the interface introduced in Windows 95 — including the taskbar, Start button and menu, and the Windows Explorer file manager — remain fundamentally unchanged in later versions of Windows, such as Windows 7 and Windows Server 2008 R2, nearly 15 years later. The word "Start" was dropped from the button in Windows Vista in 2006, with the company preferring to label the button with the Windows logo ("Start" is still present as a tooltip and in the classic GUI mode).

When released for Windows 95, Internet Explorer 4.0 came with an optional shell update known as that changed the user interface significantly. That update gave Windows 95 (and Windows NT 4.0) features that would become the graphical user interface of Windows 98.

Technical improvements

Windows 95 included support for 255-character mixed-case long filenames and preemptively multitasked pseudo-protected-mode 32-bit applications. Whereas earlier versions of Windows are optional "DOS extending shells" requiring an MS-DOS or MS- DOS compatible operating system (usually sold separately), Windows 95 incorporated MS-DOS into a consolidated operating system, which was a significant marketing change. The release of Windows 95 also marked wider acceptance of Plug and Play standards on the IBM PC platform.

Long file names

32-bit File Access is necessary for the long file names feature introduced with Windows 95 through the use of the VFAT file system. It is available to both Windows programs and MS-DOS programs started from Windows (they have to be adapted slightly, since accessing long file names requires using larger pathname buffers and hence different system calls). Competing DOS-compatible operating systems released before Windows 95 cannot see these names. Using older versions of DOS utilities to manipulate files means that the long names are not visible and are lost if files are moved or renamed, as well as by the copy (but not the original), if the file is copied. During a Windows 95 automatic upgrade of an older Windows 3.1 system, DOS and third-party disk utilities which can destroy long file names are identified and made unavailable (Microsoft Anti- Virus for Windows indicated that the upgrade program was itself a computer virus). When Windows 95 is started in DOS mode, e.g. for running DOS programs, low-level access to disks is locked out. In case the need arises to depend on disk utilities that do not recognize long file names, such as MS-DOS 6.x's defrag utility, a program called LFNBACK for backup and restoration of long file names is provided on the CD-ROM. The program is in the \ADMIN\APPTOOLS\LFNBACK directory of the Windows 95 CD-ROM.

32-bit

Windows 95 followed Windows for Workgroups 3.11 with its lack of support for older, 16-bit x86 processors, thus requiring an Intel 80386 (or compatible). The introduction of 32-bit File Access in Windows for Workgroups 3.11 meant that 16- bit real mode MS-DOS is not used for managing the files while Windows is running, and the earlier introduction of the 32-bit Disk Access means that the PC BIOS is not used for managing hard disks. This essentially reduces MS-DOS to the role of a boot loader for the protected-mode Windows kernel. DOS can be used for running old-style drivers for compatibility, but Microsoft discourages using them, as this prevents proper multitasking and impairs system stability. Control Panel allows a user to see what MS-DOS components are used by the system; optimal performance is achieved when they are all bypassed. The Windows kernel uses MS-DOS style real-mode drivers in Safe Mode, which exists to allow a user to fix problems relating to loading native, protected-mode drivers.

Internet Explorer

Windows 95 originally shipped without Internet Explorer, and the default network installation did not install TCP/IP, the network protocol used on the Internet. At the release date of Windows 95, Internet Explorer 1.0 was available, but only in the Plus! add-on pack for Windows 95, which was a separate product. The Plus! Pack did not reach as many retail consumers as the operating system itself (it was mainly advertised for its add-ons such as themes and better disk compression) but was usually included in pre- installed (OEM) sales, and at the time of Windows 95 release, the web was being browsed mainly with a variety of early web browsers such as Netscape (promoted by products such as Internet in a Box).

Windows 95 OEM Service Release 1 was the first release of Windows to include Internet Explorer (Codenamed O'Hare) with the OS, including version 2.0. While there was no uninstaller, it could be deleted easily if the user so desired. The included version switched to Internet Explorer 3 when it came out. The installation of Internet Explorer 4 on Windows 95 (or the OSR2.5 version preinstalled on a computer) gave Windows 95 active desktop and browser integration into Windows Explorer, known as the Windows Desktop Update. The CD version of the last release of Windows 95, OEM Service Release 2.5 (Version 4.00.950C), includes Internet Explorer 4, and installs it after Windows 95's initial setup and first boot is complete.

Only the 4.x series of the browser contained the Windows Desktop Update features, so anyone wanting the new shell had to install IE4 with the desktop update before installing a newer version of Internet Explorer. The last version of Internet Explorer supported on Windows 95 is Internet Explorer 5.5 which was released in 2000. Windows 95 shipped with Microsoft's own dial-up online service called The Microsoft Network.

Editions

A number of different editions of Windows 95 have been released. Only the original release was sold as a shrink-wrapped product, later editions were provided only to computer original equipment manufacturers (OEMs) for installation on new PCs. For this reason these editions are known as OEM Service Releases (OSR). Together with the introduction of Windows 95, Microsoft released the Microsoft Plus! for Windows 95 pack, which contained a number of optional components for high-end (486) multimedia PCs, including Internet Explorer, DriveSpace, and additional themes.

Microsoft initially indicated to make updates available to Windows 95 every 6 months in the form of service packs. The first service pack was made available half a year after the original release and fixed a number of small bugs.

The second service pack mainly introduced support for new hardware. Most notably support for hard drives larger than 2 GiB in the form of the FAT32 file system. This release was never made available to end-users directly and was only sold through OEMs with the purchase of a new PC.

A full third service pack was never released, but two smaller updates to the second were released in the form of a USB Supplement (OSR 2.1) and the Windows Desktop Update (OSR 2.5). Both were available as stand-alone updates and as updated disc images shipped by OEMs.

System requirements

Official system requirements were an Intel 80386 DX CPU of any speed, 4 MB of system RAM, and 120 MB of hard drive space. These minimal claims were made in order to maximize the available market of Windows 3.1 converts. This configuration was distinctly suboptimal for any productive use on anything but single tasking dedicated workstations due to the heavy reliance on virtual memory. Also, in some cases, if any networking or similar components were installed the system would refuse to boot with 4 megabytes of RAM. It was possible to run Windows 95 on a 386 SX but this led to even less acceptable performance due to its 16-bit external data bus. To achieve optimal performance, Microsoft recommends an Intel 80486 or compatible with at least 8 MB of RAM.

Windows 95 was superseded by Windows 98 and could still be directly upgraded by both Windows 2000 and Windows Me. On 31 December 2001, Microsoft ended its support for Windows 95, making it an "obsolete" product according to the Microsoft Lifecycle Policy. Even though support for Windows 95 has ended, the software still remains in use on some home and school computers because of budget issues, a lack of knowledge or lack of desire to upgrade to newer editions of Windows. In addition, some video game enthusiasts choose to use Windows 95 for their legacy system to play old DOS games, although some other versions of Windows such as Windows 98 can also be used for this purpose.

Windows 95 has been released on both floppy disks and on CD-ROM, as some computer systems at the time did not include a CD-ROM drive. The retail floppy disk version of Windows 95 came on 13 DMF formatted floppy disks, while OSR 2.1 doubled the floppy count to 26. Both versions exclude additional software that CD-ROM might have featured. Microsoft Plus! for Windows 95 was also available on floppy disks. Legacy

Many features that became key components of the Microsoft Windows series, such as the start menu and the taskbar, originated in Windows 95. Neil MacDonald, a Gartner analyst, said "If you look at Windows 95, it was a quantum leap in difference in technological capability and stability." Ina Fried of CNET said "By the time Windows 95 was finally ushered off the market in 2001, it had become a fixture on computer desktops around the world." Chapter- 6 Windows 98

Windows 98

Part of the Microsoft Windows family

Screenshot of Windows 98

Developer

Microsoft

Releases

RTM: 15 May 1998 Release date Retail: 25 June 1998 4.10.1998 (First edition, a.k.a. "Gold"); 4.10.2222A (Second Edition, a.k.a. "SE") (25 June 1998; 12 Current version years ago ("Gold"); 5 May 1999; 11 years ago ("SE"))

Source model Closed source

License Microsoft EULA

Kernel type Monolithic kernel

Support status

Unsupported as of 11 July 2006

Windows 98 (codenamed Memphis) is a graphical operating system by Microsoft. It is the second major release in the Windows 9x line of operating systems. It was released to manufacturing on 15 May 1998 and to retail on 25 June 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid 16-bit/32-bit monolithic product with an MS-DOS based boot loader. Windows 98 was succeeded by Windows 98 Second Edition on 5 May 1999, then by Windows Me (Millennium Edition) on 14 September 2000. Microsoft support for Windows 98 ended on 11 July 2006.

Web integration and shell enhancements

The Windows 98 shell includes all of the enhancements from Windows Desktop Update, an Internet Explorer 4 component, such as the Quick Launch toolbar, deskbands, Active Desktop, Channels, ability to minimize foreground windows by clicking their button on the taskbar, single click launching, Back and Forward navigation buttons, favorites, and address bar in Windows Explorer, image thumbnails, folder infotips and web view in folders, and folder customization through HTML-based templates.

Newer standards support

• Windows 98 was the first operating system to use the Windows Driver Model (WDM). This fact was not well publicised when Windows 98 was released, and most hardware producers continued to develop drivers for the older VxD driver standard, which Windows 98 also supported. The WDM standard only achieved widespread adoption years later, mostly through Windows 2000 and Windows XP, as they are not compatible with the older VxD standard. Windows Driver Model was introduced largely so that developers would write source compatible drivers for all future versions of Windows. Device driver access in WDM is actually implemented through a VxD device driver, NTKERN.VXD which implements several Windows NT-specific kernel support functions. NTKERN creates IRPs and sends them to WDM drivers. • WDM Audio: Support for WDM audio enables digital mixing, routing and processing of simultaneous audio streams and kernel streaming with high quality sample rate conversion on Windows 98. WDM Audio allows for software emulation of legacy hardware to support MS-DOS games, DirectSound support and MIDI wavetable sythesis. A Microsoft GS Wavetable Synthesizer licensed from Roland shipped with Windows 98 for WDM audio drivers. Windows 98 supports digital playback of audio CDs. Windows 98 Second Edition improves WDM audio support by adding DirectSound hardware mixing and DirectSound 3D , DirectMusic kernel support, KMixer sample-rate conversion (SRC) for capture streams and multichannel audio support. All audio is sampled by the Kernel Mixer to a fixed sampling rate which may result in some audio getting upsampled or downsampled and having a high latency, except when using Kernel Streaming or third party audio paths like ASIO which allow unmixed audio streams and lower latency. • Windows 98, in general, provides improved -- and a broader range of -- support for IDE and SCSI drives and drive controllers, floppy drive controllers and all other classes of hardware than Windows 95. • Windows 98 had more robust USB support (e.g. support for USB composite devices) than Windows 95 which only had support in OEM versions (OSR2.1 or later). Windows 98 supports USB hubs, USB scanners and imaging class devices. Windows 98 also introduces built-in support for some USB Human Interface Device class (USB HID) and PID class devices such as USB mice, keyboards, force feedback joysticks etc including additional keyboard functions through a certain number of Consumer Page HID controls. It includes a WDM streaming class driver to address real time multimedia data requirements and a WDM kernel-mode video transport for enhanced video playback and capture. USB audio device class support is present from Windows 98 SE onwards. Windows 98 Second Edition also introduced support for WDM for modems (and therefore USB modems and virtual COM ports). Microsoft driver support for both USB printers, and for USB mass-storage device class is not available for Windows 98; support for both was introduced in Windows 2000; however generic third party free drivers are available today for USB MSC devices. • Basic FireWire (IEEE 1394) support • Integrated Accelerated Graphics Port (AGP) support compared to the Windows 95 original release. (Note: USB Supplement to Windows 95 OSR2 and later releases of Windows 95 include AGP support). • DVD support and UDF 1.02 read support • ACPI 1.0 support which enabled Standby (ACPI S3) and Hibernate (ACPI S4) states. However, hibernation support was extremely limited, and vendor-specific. Hibernation was only available if compatible (PnP) hardware and BIOS are present, and the hardware manufacturer or OEM supplied compatible WDM drivers (non-VxD) drivers. There are also hibernation issues with the FAT32 file system, making hibernation problematic and unreliable. • Still imaging architecture (STI) for scanners and cameras, Image Color Management 2.0 which supports more color spaces and TWAIN support • Broadcast Driver Architecture • Multiple monitor support allows using up to 8 multiple monitors and/or multiple graphics adapters on a single PC. • Windows 98 shipped with DirectX 5.2 which notably included DirectShow. Windows 98 Second Edition shipped with DirectX 6.1.

Networking enhancements

• TCP/IP: Windows 98 networking enhancements to TCP/IP include built-in support for Winsock 2, SMB signing, a new IP Helper API, Automatic Private IP Addressing (APIPA) (also known as link-local addressing), IP multicasting (including IGMPv2 support and ICMP Router Discovery - RFC 1256), and performance enhancements for high-speed high bandwidth networks (TCP large windows and time stamps - RFC 1323, Selective Acknowledgement (SACK) - RFC 2018, TCP Fast Retransmit and Fast Recovery). Multihoming support with TCP/IP is improved and includes RIP listener support. • The DHCP client has been enhanced to include address assignment conflict detection and longer timeout intervals. NetBT configuration in the WINS client has been improved to continue persistently querying multiple WINS servers if it failed to establish the initial session until all of the WINS servers specified have been queried or a connection is established. • NDIS 5.0 support means Windows 98 can support a wide range of network media, including Ethernet, Fiber Distributed Data Interface (FDDI), token ring, Asynchronous Transfer Mode (ATM), wide area networks (WANs), ISDN, X.25, and Frame Relay. Additional features include NDIS , support for QoS, WMI and support for a single INF file format across all Windows versions. • Dial-Up Networking: Windows 98 Dial-Up Networking supports PPTP tunneling, support for ISDN adapters, multilink support, and connection-time scripting to automate non-standard login connections. Multilink channel aggregation enables users to combine all available dial-up lines to achieve higher transfer speeds. PPP connection logs can show actual packets being passed and Windows 98 allows PPP logging per connection. The Dial-Up Networking improvements are also available in Windows 95 OSR2 and downloadable for earlier Windows 95 releases. • For networked computers that have user profiles enabled, Windows 98 introduces Microsoft Family Logon which lists all users that have been configured for that computer, enabling users to simply select their names from a list rather than having to type it in. The same feature can be added to Windows 95 if Internet Explorer 4.0 is installed. • Windows 98 has built-in support for browsing DFS trees on SMB shares. • IrDA support: Windows 98 supports IrDA 3.0 that specifies both Serial Infrared Devices (SIR) and Fast Infrared (FIR) devices, which are capable of sending and receiving data at 4 Mbit/s. Infrared Recipient, a new application for transferring files through an infrared connection is included. The IrDA stack in Windows 98 supports networking profiles over the IrCOMM kernel-mode driver. • Windows 98 Second Edition added Internet Connection Sharing (IP forwarding and NAT capabilities). Windows Me later supported NAT traversal by means of UPnP. UPnP and NAT traversal APIs can also be installed on Windows 98 by installing the Windows XP Network Setup Wizard. • L2TP/IPsec VPN support as a downloadable client. • Ability to take advantage of several Windows 2000 features by installing Active Directory Client Extensions.

Improvements to the system and tools

• Microsoft Backup supports differential backup and SCSI tape devices in Windows 98. • - This tool enables users to clear their disks of unnecessary files. Cleanup locations are extensible through Disk Cleanup handlers. Disk Cleanup can be automated for regular silent cleanups. • Disk Defragmenter - Disk Defragmenter has been improved to rearrange that are frequently used to a hard disk region optimized for program start. • Scanreg (DOS) and ScanRegW — Registry Checker tool used to backup, restore or optimize the . It tests the registry's integrity and saves a backup copy each time Windows successfully boots. The maximum amount of copies could be customized by the user through "scanreg.ini" file. The restoration of a registry that causes Windows to fail to boot can only be done from DOS mode. • Msconfig — A system utility used to disable programs and services that are not required to run the computer. • Maintenance Wizard - Tool that schedules and automates ScanDisk, Disk Defragmenter and Disk Cleanup. • - Tool to check installed versions of system files to ensure they were the same version as the one installed with Windows 98 or newer. Corrupt or older versions are replaced by the correct versions. This tool was introduced to resolve the DLL hell issue and was replaced in Windows Me by System File Protection. • Fast Shutdown feature that initiates shutdown without uninitializing device drivers. • Write-behind caching for removable disk drives. • FAT32 converter utility for converting FAT16 drives to FAT32 without formatting the partition. • The Windows 98 Startup Disk contains generic, real-mode ATAPI and SCSI CD- ROM drivers and has been preconfigured to automatically start MS-DOS mode with CD-ROM support enabled. For computers without an operating system and that do not support from optical drives, the Startup disk can be used to boot into MS-DOS and automatically start Windows 98 setup from the CD. • Dr. Watson: Windows 98 includes an improved version of the Dr. Watson utility that collects and lists comprehensive information such as running tasks, startup programs with their command line switches, system patches, kernel driver, user drivers, DOS drivers and 16-bit modules. With Dr. Watson loaded in the system tray, whenever a software fault occurs (, hang, etc.), Dr. Watson will intercept it and indicate what software crashed and its cause. All of the collected information is logged to the \Windows\DrWatson folder. • WinAlign: WinAlign (Walign.exe and Winalign.exe) is a tool designed to optimize the performance of executable code (binaries). It aligns binary sections along 4 KB boundaries, aligning the executable sections with the memory pages. This allows the Windows 98 MapCache feature to map directly to sections in cache, resulting in a significant increase in performance through more available memory. Walign.exe is included in Windows 98 for optimizing programs. Winalign.exe is included in the Windows 98 Resource Kit to optimize other programs. • Windows Report Tool: Windows Report Tool takes a snapshot of system configuration and lets users submit a manual problem report along with system information to technicians. It has e- confirmation for submitted reports.

A Critical Update Notification in Windows 98

Miscellaneous improvements

• Title bars of windows and dialog boxes support two-color gradients. Windows 98 menus and tooltips support slide animation. • Windows Explorer in Windows 98, like Windows 95, converts all uppercase filenames to Sentence case for readability purposes, however, it also provides an option Allow all uppercase names to display them in their original case. • Microsoft , Accessibility Wizard and Microsoft Active Accessibility 1.1 API upgradeable to MSAA 2.0. • The system could be updated using Windows Update. A utility to automatically notify of critical updates was later released. • HTML Help and 15 Troubleshooting Wizards • upgradeable to version 5.6 • Telephony API (TAPI) 2.1 • DCOM version 1.2 • WebTV for Windows which allows viewing television on the computer if a compatible TV Tuner is installed. TV listings could updated from the Internet and WaveTop Data Broadcasting allowed extra data about broadcasts to be received via regular television signals using an antenna or cable, by embedding data streams into the vertical blanking interval (VBI) portion of existing broadcast television signals. • Windows 98 integrates shell enhancements, themes and other features from Microsoft Plus! for Windows 95 such as DriveSpace 3, Compression Agent, Dial- Up Networking Server, Dial-Up Scripting Tool and Task Scheduler. 3D Pinball is included on the CD-ROM but not installed by default. Windows 98 had its own separately purchasable Plus! pack called Plus! 98. • Ability to list fonts by similarity determined using PANOSE information. • Improved accessories: Users can configure the font in Notepad. supports GIF transparency. HyperTerminal supports a TCP/IP connection method allowing it to be used as a Telnet client. Imaging for Windows is updated. System Monitor supports logging. • Support for compressed CAB files • Tools to automate setup such as Batch 98 and INFInst.exe support error-checking, gathering information automatically to create an INF file directly from the registry of the machine, customizing IE4, shell and desktop settings and adding custom drivers. • Several other Resource Kit tools are included on the Windows 98 CD. • Besides Internet Explorer, many other internet tools were included such as , , FrontPage Express, Microsoft Chat, Personal Web Server and a Web Publishing Wizard, NetMeeting and NetShow Player (in the original release of Windows 98) which was replaced by 6.2 in Windows 98 Second Edition. • Windows 98 has new system event sounds for low battery alarm and critical battery alarm. The Windows 98 startup sound was composed by Ken Kato. • Windows 98 shipped with Flash Player and Shockwave Player preinstalled. Editions

Windows 98 Upgrade cover

Windows 98 Second Edition

Windows 98 Second Edition (often shortened to SE) is an updated release of Windows 98, released on 5 May 1999. It includes fixes for many minor issues, improved WDM audio and modem support, improved USB support and FireWire DV camcorder support, the replacement of Internet Explorer 4.0 with Internet Explorer 5.0 and related shell updates. Also included is Wake-On-LAN support (if ACPI compatible NDIS drivers are present) and Internet Connection Sharing, which allows multiple computers on a LAN to share a single Internet connection through Network Address Translation. Other features in the update include DirectX 6.1 which introduced DirectMusic, improvements to Asynchronous Transfer Mode support (IP/ATM, PPP/ATM and WinSock 2/ATM support), Windows Media Player 6.2 replacing the older Media Player, Microsoft NetMeeting 3.0, MDAC 2.1 and WMI. A memory overflow issue was resolved which in the older version of Windows 98 would crash most systems if left running for 49.7 days (equal to 2³² milliseconds). Windows 98 SE could be obtained as retail upgrade and full version packages, as well as OEM and a Second Edition Updates Disc for existing Windows 98 users. Windows 98 Second Edition did not ship with the WinG API or RealPlayer 4.0 unlike the original release of Windows 98, both of these being superceded by DirectX and Windows Media Player.

Cover of the Windows 98 Second Edition Upgrade (From Windows 95/3.1x) Box

Release Version Release Date Internet Explorer Windows 98 4.10.1998 25 June 1998 4.01 Windows 98 Second Edition 4.10.2222A 5 May 1999 5.0

Upgradeability

Several Windows 98 components which shipped at release time can be updated to newer versions. They include:

• Internet Explorer 6 SP1 • Windows Media Format Runtime and Windows Media Player 9 Series on Windows 98 SE and Windows Media Player 7.1 on Windows 98. • Windows Media Encoder 7.1 and Windows Media 8 Encoding Utility • DirectX 9.0c • MSN Messenger 7.0 • Significant features from newer Microsoft operating systems can be installed on Windows 98. Chief among them are NET Framework versions 1.0, 1.1 and 2.0, Visual C++ 2005 runtime, 2.0, GDI+ redistributable library, Remote Desktop Connection client 5.1 and the Text Services Framework. • Several other components such as MSXML 3.0 SP7, Microsoft Agent 2.0, NetMeeting 3.01, MSAA 2.0, ActiveSync 3.8, WSH 5.6, Microsoft Data Access Components 2.81 SP1, WMI 1.5 and Speech API 4.0. • Office XP is the last version of Microsoft Office to be compatible with Windows 98. • Although Windows 98 does not fully support Unicode, certain Unicode applications can run by installing the Microsoft Layer for Unicode.

Press demonstration

The release of Windows 98 was preceded by a notable press demonstration at Comdex in April 1998. Microsoft CEO was highlighting the operating system's ease of use and enhanced support for Plug and Play (PnP). However, when presentation assistant Chris Capossela plugged a scanner in and attempted to install it, the operating system crashed, displaying a Blue Screen of Death. Gates remarked after applause and cheering from the audience, "That must be why we're not shipping Windows 98 yet." Video footage of this event became a popular Internet phenomenon.

Product life cycle

Microsoft planned to discontinue its support for Windows 98 on January 16, 2004. However, due to the continued popularity of the operating system (27% of Google's pageviews were on Windows 98 systems during October-November, 2003), Microsoft decided to maintain support until July 11, 2006. Support for Windows Me also ended on this date. By that time, Windows 98 market share had diminished to 2.7%. Windows 98 is no longer available from Microsoft in any form due to the terms of Java-related settlements Microsoft made with Sun Microsystems.

System requirements

• 486DX2/66 MHz or higher processor (Pentium processor recommended) • 16 MB of RAM (24 MB recommended, it's possible to run on 8 MB machines with /nm option used during the installation process) • At least 500 MB of space available on HDD. The amount of space required depends on the installation method and the components selected, but virtual memory and system utilities as well as drivers should be taken into consideration.

• Upgrading from Windows 95 (FAT16) or 3.1 (FAT): 140-400 MB (typically 205 MB). • New installation (FAT32): 190-305 MB (typically 210 MB). • Note 1: Both Windows 98 and Windows 98 SE can have significant problems associated with hard drives that are over 32 Gigabytes (GB) in size. This issue only occurs with certain Phoenix BIOS settings. A software update has been made available to fix this shortcoming. • Note 2: Also, both Windows 98 and Windows 98 SE are unable to handle hard drives that are over 137 GB in size with the default drivers, because of missing 48-bit LBA support - whole disc data corruption is likely. Third party patches are available to fix this shortcoming.

• VGA or higher resolution monitor (640x480) • CD-ROM or DVD-ROM drive (floppy install is possible but slow) • Microsoft Mouse or compatible pointing device (optional).

Like its predecessor, Windows 95, and its successor, Windows Millennium Edition (Me), users can bypass hardware requirement checks with the undocumented /im setup . This allows installation on computers with processors as old as the 80386. Chapter- 7 Windows Me

Windows Me

Part of the Microsoft Windows family

Screenshot of Windows Me

Developer

Microsoft

Releases

Release date September 14, 2000

Current version 4.90.3000 (September 14, 2000) Source model Closed source

License Microsoft EULA

Kernel type Monolithic kernel

Support status

Unsupported as of 11 July 2006

Windows Millennium Edition, or Windows Me, is a graphical operating system released on September 14, 2000 by Microsoft. Support for Windows Me ended on July 11, 2006.

Windows Me was the successor to Windows 98 and, just like Windows 98, was targeted specifically at home PC users. It included Internet Explorer 5.5, Windows Media Player 7, and the new software, which provided basic video editing and was designed to be easy for home users. Microsoft also updated the graphical user interface and the shell features and Windows Explorer in Windows Me with some of those first introduced in Windows 2000, which had been released as a business oriented operating system seven months earlier. Windows Me could be upgraded to Internet Explorer 6 SP1, but not to SP2 (SV1) or Internet Explorer 7, and Windows Media Player 9 Series. Microsoft .NET Framework up to and including version 2.0 is supported, however versions 2.0 SP1, 3.x, and greater are not. Office XP was the last version of Microsoft Office to be compatible with Windows 9x.

Windows Me is a continuation of the Windows 9x model, but with access to real mode MS-DOS restricted in order to speed up system boot time. This was one of the most unpopular changes in Windows Me, because applications that needed real mode DOS to run, such as older disk utilities, did not run under Windows Me (although the system could be booted into real mode DOS using a bootable Windows Me floppy disk).

Compared with other releases of Windows, Windows Me had a short shelf-life of just over a year; it was soon replaced by the Windows NT-based Windows XP, which was launched on October 25, 2001. Windows Me was the last operating system in the Windows 9x series.

History

In 1998, Microsoft stated that there would be no version of Windows 9x after Windows 98. In 1999, however, Microsoft released Windows 98 Second Edition, and then announced a new version of Windows 9x which was later revealed to be codenamed Millennium. In 2000, this was released as Windows Millennium Edition (Windows Me).

At least 3 betas of Windows Me were available during its development phase. On September 24, 1999, Microsoft announced that Windows Millennium Beta 1 was released. Windows Millennium Beta 2 was released on November 24, 1999, and added a couple of new features such as System File Protection and Game Options Control Panel. Several interim builds were released between Beta 1 and 2, and added features such as automatic updates and personalized menus. Beta 3 was released on April 11, 2000. The general availability date was December 31, 2000. Microsoft ended mainstream support for Windows Millennium Edition on December 31, 2003. Extended support ended on July 11, 2006. Windows 98 Extended support ended the same day. Windows Me also contained the Microsoft Java Virtual Machine, which caused it and Windows 98 to be pulled from the Microsoft Developer Network at the end of 2003. At launch time, Microsoft announced a time-limited promotion from September 2000–January 2001 which entitled Windows 95 or Windows 98 users to upgrade to Windows Me for $59.95 instead of the regular retail upgrade price of $109.

Shortly after Windows Me was released, Microsoft launched a campaign-initiative to promote Windows Me in the U.S., which they dubbed the Meet Me Tour. A national partnered promotional program featured Windows Me, OEMs and other partners in an interactive multimedia attraction in 25 cities across the U.S.

New and updated features

Windows Me RTM CD

User interface

Windows Me featured the shell enhancements inherited from Windows 2000 such as personalized menus, customizable Windows Explorer toolbars, Windows 2000 advanced file type association features, displaying comments in shortcuts as tooltips, extensible columns in Details view (IColumnProvider interface), icon overlays, integrated search pane in Windows Explorer, sort by name function for menus, cascading Start menu special folders, some Plus! 95 and Plus! 98 themes, and updated graphics. The notification area in Windows Me and later supports 16-bit high color icons. The Multimedia control panel has also been updated from Windows 98.

Hardware support improvements

• Windows Image Acquisition: Windows Me introduced the Windows Image Acquisition API for a standardized method of allowing Windows applications to transparently and more easily communicate with image acquisition devices, such as digital cameras and scanners. WIA intended to improve the configuration and the user interface for interacting with scanners and such devices, (which were previously supported by the TWAIN standard) and simplify writing device drivers for developers. WIA also includes support for USB still image capture device classes such as scanners and cameras through the Picture Transfer Protocol. • Improved power management and suspend/resume operations: The OEM version of Windows Me supports OS-controlled ACPI S4 sleep state (hibernation) and other power management features without manufacturer-supplied drivers. Windows Me features significant improvements for improving cold boot time, pre and post-logon boot times and time required for resuming from hibernation. • USB support improvements: Windows Me is the only operating system in the Windows 9x series that includes generic drivers for USB mass storage devices and USB printers.

Digital media

• Windows Movie Maker: This utility is based on DirectShow and Windows Media technologies to provide Microsoft Windows computer systems with basic video capture and edit capabilities. It provides users with the ability to capture, edit, and re-encode media content into the Windows Media format, a tightly compressed format which requires a minimal amount of storage space on the computer's hard disk, when compared to many other media formats. • Windows Media Player 7 offers many new features and capabilities compared to previous versions, including the WindowsMedia.com guide and radio tuner which are an integral part of the player, as well as integrated jukebox and player capabilities, and interactive skins to allow consumers to personalize the look, feel, and operation of the player by changing the user interface. • Windows DVD Player: Microsoft has included a redesigned version of their DVD player in Windows Me. Unlike the Windows 98 version, the new Windows Me version supports software decoding for playback of DVD movies without a dedicated decoder card. • Image Preview: In Windows Me, images can be viewed by using the Image Preview utility. It allows users to rotate an image, print or zoom in/out an image. Image Preview supports images with .BMP, .DIB, .EMF, .GIF, .JPEG, .PNG, .TIF and .WMF file formats. The My Pictures folder also integrates previewing images. • Games: Windows Me includes version 7.1 of the DirectX API which introduced DirectPlay Voice, and also offers several new games: Internet Backgammon, Internet Checkers, Internet Hearts, Internet Reversi, Internet Spades. It also includes Spider Solitaire from Plus! 98 and Pinball from Plus! for Windows 95. The last version of DirectX available for Windows Me is DirectX 9.0c, which was released on 7 April 2006.

Networking technologies

• Net Crawler: Windows Me introduced a net crawling feature which automatically searches out and creates shortcuts to network shares and printers in My Network Places. This can be controlled using the Automatically search for network folders and printers option. Shortcuts that are added by the net crawler but not detected again on the network in a reasonable time period are aged out and deleted. • New TCP/IP Stack: Windows Me includes the Windows 2000 networking stack and architecture which was known to be more reliable, full-featured, stable and offered better performance. Support for networking over FireWire, improved infrared support, a network diagnostic troubleshooter and a new Home Networking wizard are also included. • The Home Networking Wizard is designed to help users to set up a computer that is running Windows Me for use on a small home network. This includes setting up Internet Connection Sharing (ICS) on a computer running Windows Me so the computer can share a connection to the Internet with other computers on the home network. • Dial-up Networking component was updated in Windows Me, and provides several enhancements while maintaining the desired features of prior releases of the operating system. The user interface had been reworked to provide all configurable parameters in one convenient location. The user interface now included three new tabs: Networking, Security and Dialing. To improve dial-up networking, Windows Me includes built-in support for the Connection Manager dial-up client. Using the Connection Manager Administration Kit (an optional networking component in Windows 2000 Server), network administrators can pre-configure and deploy dial-up networking connections, by means of a Connection Manager service profile, to Windows Me–based client machines. • Network Driver Interface Specification (NDIS) NDIS version 5.0 for Windows Me was enhanced to provide programming interface parity with NDIS version 5.0 in Windows 2000. This means that the programming interfaces that the author of a network device driver uses are the same for both of these Windows platforms. • Universal Plug and Play: Windows Me introduced support for Universal Plug and Play (UPnP). Universal Plug and Play and NAT traversal APIs can also be installed on Windows 98 by installing the Windows XP Network Setup Wizard.

System utilities

• : Windows Me introduced the "System Restore" logging and reversion system, which was meant to simplify troubleshooting and solve problems. It was intended to work as a rollback and recovery feature so that if the installation of an application or a driver adversely affected the system, the user could undo the installation and return the system to a previously working state. It does this by monitoring changes to Windows system files and the registry. System Restore protects only the operating system files, not documents, and therefore is not a substitute for a backup program. • System File Protection: First introduced with Windows 2000 (as ), and expanding on the capabilities introduced with System File Checker in Windows 98, System File Protection aimed to protect system files from modification and corruption silently and automatically. When the file protection is in effect, replacing or deleting a system file causes Windows Me to immediately and silently restore the original copy. The original is taken from a hard drive backup folder (%WinDir%\Options\Install) or from the Windows Me installation CD, if the cached copy of files on the hard disk has been deleted. If no installation CD is in the drive, a dialog box alerts the user about the problem and requests that the CD be inserted. System File Protection is a different technology from System Restore and should not be confused with the latter. System Restore maintains a broad set of changed files including added applications and user configuration data stored repeatedly at specific points in time restored by the user, whereas System File Protection protects operating system files with no user input. • System Configuration Utility allows users to manually extract and restore individual system files from the Windows Me setup files. It has also been updated with three new tabs called "Static VxDs", "Environment" and "International". The Static VxDs tab allows users to enable or disable static virtual device drivers to be loaded at startup, the Environment tab allows users to enable or disable environment variables, and the International tab allows users to set international language keyboard layout settings that were formerly set via the real mode MS- DOS configuration files. A Cleanup button on the Startup tab allows cleaning up invalid or deleted startup entries. • System Monitor has been updated with a Dial-Up Adapter section. Users can now monitor items such as Connection Speeds, Bytes Received or Transmitted / Second. • SCANDISK runs from within Windows upon an improper shutdown before the loads. • Automatic Updates: The Automatic Updates utility automatically downloads and installs critical updates from the Windows Update Web site with little user interaction. It is set up to check Windows Update once every 24 hours by default. Users can choose to download which update they want, although high-priority updates must be downloaded and installed.

Windows Me operating system box cover shot

• Compressed Folders: Windows Me includes support for ZIP files through a shell extension known as Compressed Folders. Originally introduced in the Plus! 98 pack for Windows 98, this feature allows users to create, access and extract files from ZIP archives similar to a regular folder in Windows. The user can also restrict access to files with a password. • On-Screen Keyboard: Originally introduced with Windows 2000, a program called On-screen Keyboard has been added, which makes it possible to input characters using the mouse instead of the keyboard. This feature is useful for computers that use a tablet as the primary pointing device or for accessibility purposes. • A new Help and Support program has also been added, replacing the HTML Help-based documentation in Windows 2000 and Windows 98. The Help and Support Center is entirely HTML-based and takes advantage of a technology called Support Automation Framework (SAF), that can show support information from the internet, allows collecting data for troubleshooting via WMI and scripting and for third parties to plug into Windows Help and Support. Several other support tools also shipped with Windows Me. • Windows Me also includes Internet Explorer 5.5 which supports a new Print Preview feature. It also shipped with the MSN Messenger Service.

Removed features

Real mode DOS

One of the most publicized changes from Windows 98 is that Windows Me does not include real mode MS-DOS. With real mode support removed, Windows Me had faster and more reliable boot performance.

The Config.sys and Autoexec.bat files are no longer read or executed during startup by IO.SYS. The command shellcommand.com is not executed and win.com is bypassed by direct execution of VMM32.VXD from IO.SYS. Because of these changes, the system can neither boot into an MS-DOS command prompt nor exit to DOS from Windows. Real mode drivers, such as ansi.sys cannot be loaded and older applications that require real mode do not run.

In Windows Me, the Autoexec.bat and Config.sys files are used only to set global environment variables. The two files (if present) are scanned for settings relating to the environment variables, and any other commands present are removed into a Windows registry key (see below). The two files thus contain only settings and preferences which configure the "global environment" for the computer during the boot phase or when starting a new MS-DOS Virtual Machine (VM).

To specify or edit other startup values (which, in Windows 98, would be present in the autoexec.bat file) the user must edit the following Windows registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\SessionManage r\Environment

For troubleshooting and crash recovery, both the Windows Me CD-ROM and the Windows Me startup disk (a user-creatable floppy disk, known as the Emergency Boot Disk) allowed booting into real mode MS-DOS.

Other components

Windows Me was aimed exclusively at home users whereas previous versions of Win9x were expected to be used in an enterprise business setting. Several features of its predecessors did not work or were officially unsupported by Microsoft on Windows Me, including Automated Installation, Active Directory client services, , Personal Web Server and ASP not supported on Windows Me although it was supported on predecessors, Windows 98 and Windows 95. A Resource Kit publication, targeted towards system administrators, was never published for Windows Me. Other features removed or never updated to work with Windows Me included Microsoft Fax, QuickView and DriveSpace.

Relation to other Windows releases

Windows Me was complemented by NT-based Windows 2000, which was aimed at professional users. Both operating systems were succeeded by Windows XP with their features unified. All Windows Me support, including security updates and security related hotfixes were terminated on July 11, 2006. Support for Windows 98 and Windows 98 SE was also terminated on that date. Microsoft ended support for these products because the company considers them obsolete and running these products can expose users to security risks.

Many third-party applications written for earlier editions of Microsoft Windows, especially older games, run under Windows Me but not under Windows 2000. This fact has become less relevant with the sharp decline in popularity of Windows Me after the release of Windows XP, which features a compatibility mode which allows many of these older applications to run.

If an installation CD-ROM from the Windows 2000 family is inserted into the drive of a computer running Windows Me, the user is prompted to upgrade to Windows 2000 because Windows Me has an older version number than Windows 2000. While this is not technically so (Windows Me was released several months after Windows 2000), Windows Me is in fact derived from the older, monolithic MS-DOS codebase (Windows 4.x) while Windows 2000 is the first of the NT 5.0 family, making the latter an upgrade.

Windows 2000 cannot, however, be upgraded to Windows Me. If an installation CD- ROM from Windows Me is inserted while running Windows 2000, the user will receive an error message that Setup cannot run from within Windows 2000. The user is prompted to shut down Windows 2000, restart the computer using Windows 95 or 98, or start MS- DOS and then run Setup from the MS-DOS command prompt.

Windows XP, which is NT-based, became the successor to Windows Me. It also closed the gap between consumer Windows and Windows NT. In addition, no service packs for Windows Me were released.

Along with Windows 2000 from the NT family, Windows Me was the last version of Windows that lacked Windows Product Activation.

Criticism

Windows Me was criticized by users for its instability and unreliability, due to frequent freezes and crashes. A PC World article dubbed Windows Me the "Mistake Edition" and placed it 4th in their "Worst Tech Products of All Time" feature. "Shortly after Me appeared in late 2000", the article states, "users reported problems installing it, getting it to run, getting it to work with other hardware or software, and getting it to stop running." The System Restore feature sometimes ended up restoring malware which the user had previously removed, since its method of keeping track of changes is fairly simplistic. By disabling System Restore, the malware could be removed, but the user lost all saved restore points.

System Restore also suffered from a bug in the date-stamping functionality that may cause System Restore to date-stamp snapshots that are taken after 8 September 2001 incorrectly. This can prevent System Restore from locating these snapshots and can cause the system restore process to fail. Microsoft released an update to fix this problem. Chapter- 8 Windows NT

Windows NT

Company / Microsoft developer

Programmed in C, C++

Working state Current

Source model Closed source / Shared source

Initial release 27 July 1993 (as Windows NT 3.1)

Windows 7, Windows Server 2008 R2 Latest stable NT 6.1 Build 7600 (7600.16385.090713- release 1255) (October 22, 2009; 14 months ago) [+/−]

Windows 7, Windows Server 2008 R2 Latest unstable Service Pack 1 RC release NT 6.1 Build 7601 (7601.17105.100929-

1730) (September 29, 2010; 2 months ago) [+/−]

Update method Windows Update

Kernel type Hybrid

Default user Graphical (Windows Explorer) interface

License MS-EULA

Official website Official website Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor- independent, , multiuser operating system with features comparable to . It was intended to complement consumer versions of Windows that were based on MS-DOS. NT was the first fully 32-bit version of Windows, whereas its consumer- oriented counterparts, Windows 3.1x and Windows 9x, were 16-bit/32-bit hybrids. Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Home Server, Windows Server 2008, and Windows 7 are based on Windows NT, although they are not branded as Windows NT.

Although various Microsoft publications, including a 1998 question-and-answer session with Bill Gates, reveal that the letters 'NT' were expanded to 'New Technology' for marketing purposes, they originally stood for "N-Ten," the codename of the XR processor for which NT was initially developed. However, they no longer carry any specific meaning.

Major features

A main design goal of NT was hardware and software portability. Various versions of NT family operating systems have been released for a variety of processor architectures, initially Intel IA-32, MIPS R3000/R4000, and Alpha, with PowerPC, Itanium, and AMD64 supported in later releases. The idea was to have a common code base with a custom Hardware Abstraction Layer (HAL) for each platform. However, support for MIPS, Alpha, and PowerPC was later dropped after NT 4.0. Broad software compatibility was achieved with support for several API "personalities", including Win32, POSIX, and OS/2 APIs - the latter two were phased out starting with Windows XP. Partial MS-DOS compatibility was achieved via an integrated DOS Virtual Machine - although this feature is being phased out in the x86-64 architecture. NT supported per-object (file, function, and role) access control lists allowing a rich set of security permissions to be applied to systems and services. NT supported Windows network protocols, inheriting the previous OS/2 LAN Manager networking, as well as TCP/IP networking (for which Microsoft would implement a TCP/IP stack derived at first from STREAMS, then later rewritten in- house.)

Windows NT 3.1 was the first version of Windows to utilize 32-bit "flat" virtual memory addressing on 32-bit processors. Its companion product, Windows 3.1, used segmented addressing and switches from 16-bit to 32-bit addressing in pages.

Windows NT 3.1 featured a core kernel providing a system API, running in supervisor mode, and a set of user-space environments with their own APIs which included the new Win32 environment, an OS/2 1.3 text-mode environment and a POSIX environment. The full preemptive multitasking kernel could interrupt running tasks to schedule other tasks, without relying on user programs to voluntarily give up control of the CPU, as in Windows 3.1 Windows applications (although MS-DOS applications were preemptively multitasked in Windows starting with Windows 1.0). Notably, in Windows NT 3.x, several I/O driver subsystems, such as video and printing, were user-mode subsystems. In Windows NT 4, the video, server, and printer spooler subsystems were integrated into the kernel. Windows NT's first GUI was strongly influenced by (and programmatically compatible with) that from Windows 3.1; Windows NT 4's interface was redesigned to match that of the brand new Windows 95, moving from the Program Manager to the Start Menu/Taskbar design.

NTFS, a journaled, secure file system, was created for NT. Windows NT also allows for other installable file systems, and with versions 3.1 and 3.51, NT could also be installed on DOS's FAT or OS/2's HPFS file systems. Later versions could be installed on a FAT32 partition, in select cases, including Vista versions. Windows Vista and Windows 7 require a FAT32 partition to boot on an EFI based system.

Development

Microsoft decided to create a portable operating system, compatible with OS/2 and POSIX and suppporting multiprocessing, in October 1988. When development started in November 1989, Windows NT was to be known as OS/2 3.0, the third version of the operating system developed jointly by Microsoft and IBM. To ensure portability, initial development was targeted at the Intel i860XR RISC processor, switching to the MIPS R3000 in late 1989, and then the Intel i386 in 1990. Microsoft also continued parallel development of the DOS-based and less resource-demanding Windows environment, resulting in the release of Windows 3.0 in May 1990. Windows 3 was eventually so successful that Microsoft decided to change the primary application programming interface for the still unreleased NT OS/2 (as it was then known) from an extended OS/2 API to an extended Windows API. This decision caused tension between Microsoft and IBM and the collaboration ultimately fell apart. IBM continued OS/2 development alone while Microsoft continued work on the newly renamed Windows NT. Though neither operating system would immediately be as popular as Microsoft's MS-DOS or Windows products, Windows NT would eventually be far more successful than OS/2.

Microsoft hired a group of developers from Digital Equipment Corporation led by Dave Cutler to build Windows NT, and many elements of the design reflect earlier DEC experience with Cutler's VMS and RSX-11. The operating system was designed to run on multiple instruction set architectures and multiple hardware platforms within each architecture. The platform dependencies are largely hidden from the rest of the system by a kernel mode module called the HAL (Hardware Abstraction Layer).

Windows NT's kernel mode code further distinguishes between the "kernel", whose primary purpose is to implement processor and architecture dependent functions, and the "executive". This was designed as a modified , as the Windows NT kernel does not meet all of the criteria of a pure microkernel. Both the kernel and the executive are linked together into the single loaded module ntoskrnl.exe; from outside this module there is little distinction between the kernel and the executive. Routines from each are directly accessible, as for example from kernel-mode device drivers. API sets in the Windows NT family are implemented as subsystems atop the publicly undocumented "native" API; this allowed the late adoption of the Windows API (into the Win32 subsystem). Windows NT was one of the earliest operating systems to use Unicode internally.

Driver models

Windows NT introduced its own driver model, the Windows NT driver model, and is incompatible with older driver frameworks. With Windows 2000, the Windows NT driver model was enhanced to become the Windows Driver Model, which was first introduced with Windows 98, but was based on the NT driver model. Windows Vista added native support for the Windows Driver Foundation, which is also available for Windows XP, Windows Server 2003 and to an extent, Windows 2000.

Releases Windows NT releases Marketing Release RTM Version Editions name date build Windows NT (named just Windows NT 3.1 27 July 1993 528 3.1 NT), Advanced Server 21 Windows NT NT 3.5 Workstation, Server September 807 3.5 1994 Windows NT 30 May NT 3.51 Workstation, Server 1057 3.51 1995 Workstation, Server, Server Windows NT NT 4.0 Enterprise Edition, Terminal Server, 29 July 1996 1381 4.0 Embedded Professional, Server, Advanced Server, Datacenter Server, 17 February NT 5.0 Windows 2000 2195 Advanced/Datacenter Server Limited 2000 Edition Home, Professional, 64-bit Edition (Itanium), Media Center (original, 25 October NT 5.1 Windows XP 2003, 2004 & 2005), Tablet PC 2600 2001 (original and 2005), Starter, Embedded, Home N, Professional N Windows NT 5.1 Fundamentals N/A 8 July 2006 2600 for Legacy PCs 28 March NT 5.2 Windows XP 64-bit Edition Version 2003 (Itanium) 3790 2003 NT 5.2 Windows Server Standard, Enterprise, Datacenter, 24 April 3790 2003 Web, Storage, Small Business Server, 2003 Compute Cluster 25 April NT 5.2 Windows XP Professional x64 Edition 3790 2005 Windows Home NT 5.2 N/A 16 July 2007 3790 Server Business: 30 November Starter, Home Basic, Home Premium, 6000 2006 NT 6.0 Windows Vista Business, Enterprise, Ultimate, Home 6001(SP1) Consumer: Basic N, Business N 6002(SP2) 30 January 2007 Foundation, Standard, Enterprise, Windows Server 27 February 6001 NT 6.0 Datacenter, Web Server, HPC Server, 2008 2008 6002(SP2) Itanium-Based Systems Starter, Home Basic, Home Premium, 22 October NT 6.1 Windows 7 7600 Professional, Enterprise, Ultimate 2009 Foundation, Standard, Enterprise, Windows Server 22 October NT 6.1 Datacenter, Web Server, HPC Server, 7600 2008 R2 2009 Itanium-Based Systems

Windows NT 3.1 to 3.51 incorporated the Program Manager and File Manager from the Windows 3.x series. Windows NT 4.0 onwards replaced those programs with Windows Explorer (including a taskbar and Start menu), which originally appeared in Windows 95.

The first release was given version number 3.1 to match the contemporary 16-bit Windows; magazines of that era claimed the number was also used to make that version seem more reliable than a '.0' release. There were also some issues related to Novell IPX protocol licensing, which was apparently limited to 3.1 versions of Windows software.

The NT version number is not now generally used for marketing purposes, but is still used internally, and said to reflect the degree of changes to the core of the operating system. The build number is an internal identifier used by Microsoft's developers and beta testers.

Supported platforms

NT was written in C and C++, and is reasonably portable, although (as of 2009) only three architectures are currently supported. That said, it proved far more difficult to port applications such as Microsoft Office which were sensitive to issues such as data structure alignment on RISC processors. Unlike Windows CE which routinely runs on a variety of processors, the lack of success of RISC-based systems in the desktop market has resulted in nearly all NT deployments being on x86 architecture processors. In order to prevent Intel x86-specific code from slipping into the operating system by developers used to developing on x86 chips, Windows NT 3.1 was initially developed using non-x86 development systems and then ported to the x86 architecture. This work was initially based on the Intel i860-based Dazzle system and, later, the MIPS R4000- based Jazz platform. Both systems were designed internally at Microsoft.

Windows NT 3.1 was released for Intel x86 PC compatible, DEC Alpha, and ARC- compliant MIPS platforms. Windows NT 3.51 added support for the PowerPC processor in 1995, specifically PReP-compliant systems such as the IBM Power Series desktops/laptops and Motorola PowerStack series; but despite meetings between Michael Spindler and Bill Gates, not on the Power Macintosh as the PReP compliant Power Macintosh project failed to ship.

Intergraph Corporation ported Windows NT to its Clipper architecture and later announced intention to port Windows NT 3.51 to Sun Microsystems' SPARC architecture, but neither version was sold to the public as a retail product.

Only two of the Windows NT 4.0 variants (IA-32 and Alpha) have a full set of service packs available. All of the other ports done by third parties (Motorola, Intergraph, etc.) have few, if any, publicly available updates.

Windows NT 4.0 was the last major release to support Alpha, MIPS, or PowerPC, though development of Windows 2000 for Alpha continued until August 1999, when Compaq stopped support for Windows NT on that architecture; and then three days later Microsoft also canceled their AlphaNT program, even though the Alpha NT 5 (Windows 2000) release had reached RC2 (build 2128).

Released versions of NT for Alpha were 32-bit only. The 64 bit port of Windows was originally intended to run on Itanium as well as on Alpha, and Alpha hardware was accordingly used internally at Microsoft during early development of 64-bit Windows. This continued for some time after Microsoft publicly announced that it was cancelling plans to ship 64-bit Windows for Alpha, because Itanium hardware was not yet available for development.

Limited Editions of Windows 2000 Advanced Server and Datacenter Server, Windows XP 64-Bit, and Windows Server 2003 Enterprise and Datacenter support Intel's IA-64 processors.

As of June 2010, Microsoft have released seventeen editions for the x64 processor architecture:

• Windows XP Professional x64 Edition • Windows Server 2003 Standard x64 Edition • Windows Server 2003 Enterprise x64 Edition • Windows Server 2003 Datacenter x64 Edition • Windows Vista Home Basic x64 Edition • Windows Vista Home Premium x64 Edition • Windows Vista Enterprise x64 Edition • Windows Vista Ultimate x64 Edition • Windows Server 2008 Web Server x64 Edition • Windows Server 2008 Standard x64 Edition • Windows Server 2008 Enterprise x64 Edition • Windows Server 2008 Datacenter x64 Edition • Windows 7 Home Basic x64 Edition • Windows 7 Home Premium x64 Edition • Windows 7 Professional x64 Edition • Windows 7 Enterprise x64 Edition • Windows 7 Ultimate x64 Edition.

According to Microsoft, it is a common misconception that the and Xbox 360 use a modified Windows 2000 kernel. They claim that the Xbox operating system was built from scratch but implements a subset of Windows APIs. The idea that it does, indeed, run a modified copy of the Windows kernel still persists in the community.

Hardware requirements

The minimum hardware specification required to run each release of the professional workstation version of Windows NT has been fairly slow-moving until the 6.0 Vista release, which requires a minimum of 15 GB of free disk space, a 10-fold increase in free disk space alone over the previous version.

Windows NT desktop (x86) minimum hardware requirements NT version CPU RAM Free disk space NT 3.1 12 MB 386, 25 MHz 90 MB NT 3.1 Advanced Server 16 MB NT 3.5 Workstation 12 MB 386, 25 MHz 90 MB NT 3.5 Server 16 MB NT 3.51 Workstation 12 MB 386, 25 MHz 90 MB NT 3.51 Server 16 MB NT 4.0 Workstation 12 MB 486, 25 MHz 124 MB NT 4.0 Server 16 MB 2000 Professional 32 MB Pentium, 133 MHz 650 MB 2000 Server 128 MB XP Pentium, 233 MHz 64* MB 1.5 GB Server 2003 Pentium, 133 MHz 128 MB 1.5 GB Vista Pentium III, 800 MHz 512 MB 15 GB 7 Pentium III, 1 GHz 1 GB 16 GB

*Windows XP can be run at 64 MB RAM. Some features require 128 MB RAM. Designation

It is popularly believed that Dave Cutler intended the initialism 'WNT' as a pun on VMS, incrementing each letter by one. However, the project was named NT OS/2 before receiving the Windows brand. One of the original OS/2 3.0 developers, Mark Lucovsky, states that the name was taken from the original target processor—the Intel i860, code- named N10 ('N-Ten'). Various Microsoft publications, including a 1998 question-and- answer session with Bill Gates, reveal that the letters were expanded to 'New Technology' for marketing purposes but no longer carry any specific meaning. The letters were dropped from the name of Windows 2000, though Microsoft described the product as 'Built on NT technology.' Chapter- 9 Windows CE

Windows CE

Company / developer Microsoft

Programmed in C

OS family Windows CE

Source model Closed source (shared source kernel)

Initial release 16 November 1996; 14 years ago

Latest stable release 6.0 R3 / 22 September 2009; 14 months ago

Available language(s) Multilingual

Supported platforms x86, MIPS, ARM, (SuperH up to 6.0 R2)

Monolithic Kernel type Hybrid

License MS-EULA

Windows CE (also known officially as Windows Embedded Compact or Windows Embedded CE post version 6.0, and sometimes abbreviated WinCE) is an operating system developed by Microsoft for minimalistic computers and embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows. It is not to be confused with Windows XP Embedded which is NT-based. Microsoft licenses Windows CE to OEMs and device makers. The OEMs and device makers can modify and create their own user interfaces and experiences, while Windows CE provides the technical foundation to do so.

Windows CE is supported on Intel x86 and compatibles, MIPS, ARM, and Hitachi SuperH processors.

Features

Windows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of memory. Devices are often configured without disk storage, and may be configured as a “closed” system that does not allow for end-user extension (for instance, it can be burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. From version 3 and onward, the system supports 256 priority levels and uses priority inheritance for dealing with priority inversion. The fundamental unit of execution is the . This helps to simplify the interface and improve execution time.

Microsoft has stated that the ‘CE’ is not an intentional initialism, but many people believe CE stands for ‘Consumer Electronics’ or ‘Compact Edition’. Microsoft says it implies a number of Windows CE design precepts, including “Compact, Connectable, Compatible, Companion, and Efficient.” The first version, known during development under the code name “Pegasus”, featured a Windows-like GUI and a number of Microsoft's popular applications, all trimmed down for smaller storage, memory, and speed of the palmtops of the day.

Since then, Windows CE has evolved into a component-based, embedded, real-time operating system. It is no longer targeted solely at hand-held computers. Many platforms have been based on the core Windows CE operating system, including Microsoft's AutoPC, Pocket PC 2000, Pocket PC 2002, Windows Mobile 2003, Windows Mobile 2003 SE, Windows Mobile 5.0, Windows Mobile 6, Smartphone 2002, Smartphone 2003, Portable Media Center and many industrial devices and embedded systems. Windows CE even powered select games for the Dreamcast, was the operating system of the Gizmondo handheld, and can partially run on modified Xbox game consoles.

A distinctive feature of Windows CE compared to other Microsoft operating systems is that large parts of it are offered in source code form. First, source code was offered to several vendors, so they could adjust it to their hardware. Then products like Platform Builder (an integrated environment for Windows CE OS image creation and integration, or customized operating system designs based on CE) offered several components in source code form to the general public. However, a number of core components that do not need adaptation to specific hardware environments (other than the CPU family) are still distributed in binary only form. Development tools

Visual Studio

Microsoft Visual Studio 2008 and earlier support projects for Windows CE / Windows Mobile, producing executable programs and platform images either as an emulator or attached by cable to an actual mobile device. A mobile device is not necessary to develop a CE program. The .NET Compact Framework supports a subset of the .NET Framework with projects in C#, and VB.NET, but not Managed C++.

Microsoft removed this feature from Visual Studio 2010. A standalone IDE for Windows Phone 7 (the Windows Phone Developer Tools) is available instead.

CodeGear Delphi Prism

CodeGear Delphi Prism, which runs in Visual Studio, also supports the .NET Compact Framework and thus can be used to develop mobile applications. It employs the Oxygene compiler created by RemObjects, which targets .NET, the .NET Compact Framework, and Mono. Its command-line compiler is available free of charge.

Free Pascal and Lazarus

Free Pascal introduced the Windows CE port in version 2.2.0, targeting ARM and x86 architectures. Later the Windows CE header files were translated for use with Lazarus, a rapid application development (RAD) software package based on Free Pascal. Windows CE applications are designed and coded in the Lazarus integrated development environment (IDE) and compiled with an appropriate cross compiler.

Basic4ppc

Basic4ppc which is a similar to Visual Basic, targets the .NET Compact Framework and supports Windows CE and Windows Mobile devices.

GLBasic

GLBasic is a very easy to learn and use BASIC dialect that compiles for many platforms, including Windows CE and Windows Mobile. It can be extended by writing inline C/C++ code.

Platform Builder

This programming tool is used for building the platform (BSP + Kernel), device drivers (shared source or custom made) and also the application. This is a one step environment to get the system up and running. One can also use Platform Builder to export an SDK (software development kit) for the target microprocessor (SuperH, x86, MIPS, ARM etc.) to be used with another associated tool set named below. Embedded Visual C++ (eVC)

The Embedded Visual C++ tool is for development of embedded application for Windows CE based devices. This tool can be used standalone using the SDK exported from Platform Builder or using the Platform Builder using the Platform Manager connectivity setup.

AutoHotkey

A port of the open source macro-creation and automation software utility AutoHotkey is available for Windows CE, which allows the construction of macros and simple GUI applications developed by systems analyst Jonathan Maxian Timkang.

Relationship to Windows Mobile, Pocket PC, and SmartPhone

Timeline of Windows CE Development

Often Windows CE, Windows Mobile, and Pocket PC are used interchangeably - in part due to their common origin. This practice is not entirely accurate. Windows CE is a modular/componentized operating system that serves as the foundation of several classes of devices. Some of these modules provide subsets of other components' features (e.g. varying levels of windowing support; DCOM vs COM), others which are separate (Bitmap or TrueType font support), and others which add additional features to another component. One can buy a kit (the Platform Builder) which contains all these components and the tools with which to develop a custom platform. Applications such as Excel Mobile/Pocket Excel are not part of this kit. The older Handheld PC version of Pocket Word and several other older applications are included as samples, however.

Windows Mobile is best described as a subset of platforms based on a Windows CE underpinning. Currently, Pocket PC (now called Windows Mobile Classic), SmartPhone (Windows Mobile Standard), and Pocket PC Phone Edition (Windows Mobile Professional) are the three main platforms under the Windows Mobile umbrella. Each platform uses different components of Windows CE, plus supplemental features and applications suited for their respective devices.

Pocket PC and Windows Mobile is a Microsoft-defined custom platform for general PDA use, and consists of a Microsoft-defined set of minimum profiles (Professional Edition, Premium Edition) of software and hardware that is supported. The rules for manufacturing a Pocket PC device are stricter than those for producing a custom Windows CE-based platform. The defining characteristics of the Pocket PC are the digitizer as the primary human interface device and its extremely portable size.

The SmartPhone platform is a feature rich OS and interface for cellular phone handsets. SmartPhone offers productivity features to business users, such as email, and multimedia abilities for consumers. The SmartPhone interface relies heavily on joystick navigation and PhonePad input. Devices running SmartPhone do not include a touchscreen interface. SmartPhone devices generally resemble other cellular handset form factors, whereas most Phone Edition devices use a PDA form factor with a larger display.

Versions Version Changes Released in 16 November 1996 [MSCE1]. Codename "Alder". 1.0 • Devices named "handheld PC" (HPC).

Released in September 1997 [MSCE2]. Codename "Birch".

• Devices named "Palm-sized PC". • Real-time deterministic task scheduling. 2.0 • Architectures: ARM, MIPS, PowerPC, StrongARM, SuperH and x86. • 32-bit color screens. • SSL 2.0 and SSL 3.0.

Released in June 2000 [MSCE3]. Codename "Cedar".

• Major recode that made CE hard real time down to the microsecond 3.0 level. • Base for the Pocket PC 2000, Handheld PC 2000, Pocket PC 2002 and Smartphone 2002. • Priority levels was increased from 8 to 256. • Object store was increased from 65 536 to 4,19 million allowed objects. • Restricted access to critical APIs or restricting write access to parts of the registry.

Released in January 2002 [MSCE4]. Codename "Talisker/Jameson/McKendric".

Driver structure changed greatly, new features added. 4.x • Base for "Pocket PC 2003". • Bluetooth support. • TLS (SSL 3.1), IPsec L2TP VPN, or Kerberos.

Released in August 2004. Adds lots of features. Codename "Macallan".

• Automatic report of bugs to the manufacturer. • Direct3D Mobile, a COM-based version of Windows XP's DirectX 5.x multimedia API. • DirectDraw for 2D graphics and DirectShow for camera and video digitisation support. • Remote Desktop Protocol (RDP) support.

Released in September 2006. Codename "Yamazaki".

• Process address space is increased from 32 MB to 2 GB. • Number of processes has been increased from 32 to 32 768. • User mode and kernel mode device drivers are possible. 6.0 • 512MB physically managed memory • Device.exe, filesys.exe, GWES.exe has been moved to Kernel mode. • SetKMode and set process permissions not possible. • System call performance improved.

Releasing Q1 2011.

• Dual-core CPU support (SMP, ARMv6) • Wi-Fi Positioning System • Bluetooth 3.0 + HS • Cellcore 7.0 • DLNA (Digital Living Network Alliance) • DRM technology • Media Transfer Protocol • Windows Phone 7 IE with Flash 10.1 support • NDIS 6.1 support • UX C++ XAML API using technologies like Windows Presentation Foundation and Silverlight for attractive and functional user interfaces • Advance touch and gesture input • Kernel support for 3GB physical RAM and supports ARMv7 assembly

CE v3.0 is the basis for Pocket PC 2002. A successor to CE v3.0 is CE.net. "PocketPC [is] a separate layer of code on top of the core Windows CE OS... Pocket PC is based on Windows CE, but it's a different offering." And licensees of Pocket PC are forbidden to modify the WinCE part. Chapter- 10 Windows 9x

Windows 9x

Screenshot of Windows 95, the first version of Windows in the 9x series

Company / developer Microsoft

OS family Microsoft Windows

Working state Unsupported

Source model Closed Source

Supported platforms IA-32

Kernel type Monolithic Kernel

Userland win32, win16, MS-DOS

License MS-EULA Windows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced since 1995, which were based on the original and later modified Windows 95 kernel. This includes all versions of Windows 95, Windows 98 and often also Windows Me.

Internal release versions for versions of Windows 9x are "4.x", where previous MS-DOS based versions of Windows used version numbers of 3.2 or less. Windows NT used a similar but separate version number between 3.5 and 4.0. The first successor to Windows Me (with internal version 4.9), Windows XP, used Version 5.1.

Windows 9x is predominantly known for its use in desktops; in 1998 Windows made up 82% of operating system market share.

Most of the feature set and compatibility of the Windows 9x line of operating systems was merged with Windows NT with the release of Windows XP, which was the successor to both Windows 2000 and Windows Me.

History

Windows prior to 95

The first independent version of Microsoft Windows, version 1.0, released on 20 November 1985, achieved little popularity. It was originally going to be called "Interface Manager" but Rowland Hanson, the head of marketing at Microsoft, convinced the company that the name Windows would be more appealing to consumers. Windows 1.0 was not a complete operating system, but rather an "operating environment" that extended MS-DOS, and shared the latter's inherent flaws and problems.

Microsoft Windows version 2 came out on 9 December 1987, and used the real-mode memory model, which confined it to a maximum of 1 megabyte of memory. In such a configuration, it could run under another multitasker like DESQview, which used the 286 Protected Mode.

Microsoft Windows scored a significant success with Windows 3.0, released in 1990. In addition to improved capabilities given to native applications, Windows also allowed users to better multitask older MS-DOS based software compared to Windows/386, thanks to the introduction of virtual memory.

Microsoft developed Windows 3.1, which included several minor improvements to Windows 3.0, but primarily consisted of bugfixes and multimedia support. It also excluded support for Real mode, and only ran on an 80286 or better processor. Later Microsoft also released Windows 3.11, a touch-up to Windows 3.1 which included all of the patches and updates that followed the release of Windows 3.1 in 1992.

Meanwhile Microsoft continued to develop Windows NT. The main architect of the system was Dave Cutler, one of the chief architects of VMS at Digital Equipment Corporation (later purchased by Compaq, now part of Hewlett-Packard). Microsoft hired him in August 1988 to create a successor to OS/2, but Cutler created a completely new system instead.

Microsoft announced at the conference its intentions to develop a successor to both Windows NT and Windows 3.1's replacement (Windows 95, code-named Chicago), which would unify the two into one operating system. This successor was codenamed Cairo. In hindsight, Cairo was a much more difficult project than Microsoft had anticipated and, as a result, NT and Chicago would not be unified until Windows XP.

Windows 95

Windows 95 Logo

After Windows 3.11, Microsoft began to develop a new consumer oriented version of the operating system code-named Chicago. Chicago was designed to have support for 32-bit preemptive multitasking like OS/2 and Windows NT, although a 16-bit kernel would remain for the sake of backward compatibility. The Win32 API first introduced with Windows NT was adopted as the standard 32-bit programming interface, with Win16 compatibility being preserved through a technique known as "thunking". A new GUI was not originally planned as part of the release, although elements of the Cairo user interface were borrowed and added as other aspects of the release (notably Plug and Play) slipped.

Microsoft did not change all of the Windows code to 32-bit; parts of it remained 16-bit (albeit not directly using real mode) for reasons of compatibility, performance and development time. Additionally it was necessary to carry over design decisions from earlier versions of Windows for reasons of backwards compatibility, even if these design decisions no longer matched a more modern computing environment. These factors eventually began to impact the operating system's efficiency and stability.

Microsoft marketing adopted Windows 95 as the product name for Chicago when it was released on August 24, 1995.

Microsoft went on to release five different versions of Windows 95:

• Windows 95 - original release • Windows 95 A - included Windows 95 OSR1 slipstreamed into the installation. • Windows 95 B - (OSR2) included several major enhancements, Internet Explorer (IE) 3.0 and full FAT32 file system support. • Windows 95 B USB - (OSR2.1) included basic USB support. • Windows 95 C - (OSR2.5) included all the above features, plus IE 4.0. This was the last 95 version produced. OSR2, OSR2.1 and OSR2.5 were not released to the general public; rather, they were available only to OEMs that would preload the OS onto computers. Some companies sold new hard drives with OSR2 preinstalled (officially justifying this as needed due to the hard drive's capacity).

The first Microsoft Plus! add-on pack was sold for Windows 95.

Windows 98

Windows 98 logo

On 25 June 1998, Microsoft released Windows 98. It included new hardware drivers and better support for the FAT32 file system which allows support for disk partitions larger than the 2 GB maximum accepted by Windows 95. The USB support in Windows 98 is more robust than the basic support provided by the OEM editions of Windows 95. It also controversially integrated the Internet Explorer browser into the Windows GUI and Windows Explorer file manager.

In 1999, Microsoft released Windows 98 Second Edition, an interim release whose notables features were the addition of Internet Connection Sharing and improved WDM audio and modem support. Internet Connection Sharing is a form of network address translation, allowing several machines on a LAN (Local Area Network) to share a single Internet connection. Windows 98 Second Edition has certain improvements over the original release. Hardware support through device drivers was increased. Many minor problems present in the original Windows 98 were found and fixed which make it, according to many, the most stable release of Windows 9x family—to the extent that commentators used to say that Windows 98's beta version was more stable than Windows 95's final (gamma) version.

Windows Me

In September 2000, Microsoft introduced Windows Me (Millennium Edition), which upgraded Windows 98 with enhanced multimedia and Internet features. It also introduced the first version of system restore, which allowed users to revert their system state to a previous "known-good" point in the case of system failure. The first version of Windows Movie Maker was introduced as well.

Windows Me was conceived as a quick one-year project that served as a stopgap release between Windows 98 and Windows XP. Many of the new features were available from the Windows Update site as updates for older Windows versions. As a result, Windows Me was not acknowledged as a unique Operating System along the lines of 95 or 98, and is often included in the Windows 9x series. Windows Me was criticized by users for its instability and unreliability, due to frequent freezes and crashes. A PC World article dubbed Windows Me the "Mistake Edition" and placed it 4th in their "Worst Tech Products of All Time" feature.

The inability of users to easily boot into MS-DOS mode, as in Windows 95 or 98, led users to quickly learn how to hack their Windows Me installations to provide the needed service.

Decline

The release of Windows 2000 marked a shift in the user experience between the Windows 9x series and the Windows NT series. Where NT4 suffered from a lack of USB support, Plug and Play support, and an aging, difficult to use, archaic-looking interface, Windows 2000 had a modern interface, and better USB and plug and play support than any version of Windows 9x.

The release of Windows XP signalled a change of direction for Microsoft, bringing the consumer and business Operating Systems together.

One by one, support for the Windows 9x series ended, and Microsoft stopped selling the software to end users, then later to OEMs. By March 2004, it was impossible to purchase any copy of any Windows in the 9x series.

End of Service life

Microsoft continued to support the use of the Windows 9x series, however, until July 11, 2006, when extended support ended for the software.

Microsoft DirectX, a set of standard gaming APIs, stopped being updated on Windows 95 at Version 8.0a. Windows 98 and ME stopped being updated at version 9, and DirectX 10 ships with and is only available with Windows Vista and later; previous versions of Windows are not able to officially run DirectX 10-exclusive applications.

Microsoft Internet Explorer 7, the first major update for the aged and insecure Internet Explorer 6 in half a decade, was only available for Windows XP SP2 or later.

The growing number of important updates caused by the end of service life of these pieces of software have slowly made Windows 9x less and less practical for everyday use. Today, even open source projects such as Mozilla won't run on Windows 9x without rework.

Design

Kernel

Windows 9x is a series of hybrid 16/32-bit operating systems. Like most operating systems, Windows 9x consists of kernel space and memory.

Although Windows 9x features memory protection, it does not protect the first megabyte of memory from userland applications. This area of memory contains code critical to the functioning of the operating system, and by writing into this area of memory an application can crash or freeze the operating system. This was a source of instability as faulty applications could by accident write into this region and with that halt the operating system.

User Mode

The user-mode parts of Windows 9x consist of three subsystems: the Win16 subsystem, the Win32 subsystem and MS-DOS.

Windows 9x/Me set aside two blocks of 64 KB memory regions for GDI and heap resources. By running multiple applications, applications with numerous GDI elements or by running applications over a long span of time, it could exhaust these memory areas. If free system resources dropped below 10%, Windows would become unstable and likely crash.

Kernel Mode

The kernel mode parts consist of the Virtual Machine Manager (VMM), the Installable File System Manager (IFSHLP), the Configuration Manager, and in Windows 98 and later, the WDM Driver Manager (NTKERN). As a 32-bit operating system, virtual memory space is 4 GiB, divided into a lower 2 GiB for applications and an upper 2 GiB for kernel per process.

Registry

Like Windows NT, Windows 9x stores user-specific and configuration-specific settings in a large information database called the Windows registry. Hardware-specific settings are also stored in the registry, and many device drivers use the registry to load configuration data. Previous versions of Windows used files such as AUTOEXEC.BAT, CONFIG.SYS, WIN.INI, SYSTEM.INI and other files with an .INI extension to maintain configuration settings. As Windows became more complex and incorporated more features, .INI files became too unwieldy for the limitations of the then-current FAT filesystem. Backwards-compatibility with .INI files was maintained until Windows XP succeeded the 9x and NT lines.

Although Microsoft discourages using .INI files in favor of Registry entries, a large number of applications (particularly 16-bit Windows-based applications) still use .INI files. Windows 9x supports .INI files solely for compatibility with those applications and related tools (such as setup programs). The AUTOEXEC.BAT and CONFIG.SYS files also still exist for compatibility with real-mode system components and to allow users to change certain default system settings such as the PATH environment variable.

The registry consists of two files: User.dat and System.dat. In Windows Me, Classes.dat was added.

Virtual Machine Manager

The Virtual Machine Manager (VMM) is the 32-bit protected mode kernel at the core of Windows 9x. Its primary responsibility is to create, run, monitor and terminate virtual machines. The VMM provides services that manage memory, processes, and protection faults. The VMM works with virtual devices (loadable kernel modules, which consist mostly of 32-bit ring 0 or kernel mode code, but may include other types of code, such as a 16-bit real mode initialisation segment) to allow those virtual devices to intercept interrupts and faults to control the access that an application has to hardware devices and installed software. Both the VMM and virtual device drivers run in a single, 32-bit, flat model address space at privilege level 0 (also called ring 0). The VMM provides multi-threaded, preemptive multitasking. It runs multiple applications simultaneously by sharing CPU () time between the threads in which the applications and virtual machines run.

The VMM is also responsible for creating MS-DOS environments for system processes and Windows applications that still need to run in MS-DOS mode. It is the replacement for Win386 in Windows 3.x, and the file vmm32.vxd is a compressed archive containing most of the core VxD, including VMM.vxd itself and ifsmgr.vxd (which facilitates file system access without the need to call the real mode file system code of the DOS kernel).

Software Support

File Systems

Windows 9x does not natively support NTFS or HPFS, but there are third-party solutions which allow Windows 9x to have read-only access to NTFS volumes.

Early versions of Windows 95 did not support FAT32.

Like Windows for Workgroups 3.11, Windows 9x provides support for 32-bit file access, and unlike Windows 3.x, Windows 9x has support for the VFAT file system, allowing file names with a maximum of 255 characters instead of having 8.3 filenames.

Event Logging and Tracing

Also, there is no support for event logging and tracing or error reporting which the Windows NT family of operating systems has, although software like Norton CrashGuard can be used to achieve similar capabilities on Windows 9x. Security

Windows 9x is designed as a single-user system. Thus, the security model is much less effective than the one in Windows NT. One reason for this is the FAT file systems (including FAT12/16/32), which are the only ones that Windows 9x supports officially, though Windows NT also supports FAT 12 and 16 (but not 32) and Windows 9x can be extended to read and write NTFS volumes using third-party Installable File System drivers. FAT systems have very limited security; every user that has access to a FAT drive also has access to all files on that drive. The FAT file systems provide no access control lists and file-system level encryption like NTFS.

Some operating systems that were available at the same time as Windows 9x are either multi-user or have multiple user accounts with different access privileges, which allows important system files (such as the kernel image) to be immutable under most user accounts. In contrast, while Windows 95 and later operating systems offer the option of having profiles for multiple users, they have no concept of access privileges, making them roughly equivalent to a single-user, single-account operating system; this means that all processes can modify all files on the system that aren't open, in addition to being able to modify the boot sector and perform other low-level hard drive modifications. This enables viruses and other clandestinely installed software to integrate themselves with the operating system in a way that is difficult for ordinary users to detect or undo. The profile support in the Windows 9x family is meant for convenience only; unless some registry keys are modified, the system can be accessed by pressing "Cancel" at login, even if all profiles have a password. Windows 95's default login dialog box also allows new user profiles to be created without having to log in first.

Users and software can render the operating system unable to function by deleting or overwriting important system files from the hard disk. Users and software are also free to change configuration files in such a way that the operating system is unable to boot or properly function.

Installation software often replaced and deleted system files without properly checking if the file was still in use or of a newer version. This created a phenomenon often referred to as DLL hell.

Windows Me introduced System File Protection and System Restore to handle common problems caused by this issue.

DOS's FAT and FAT32 filesystem inhereited by Windows 9x have neither file protection nor file permissions of NTFS.

Network Sharing

Windows 9x offers share-level access control security for file and printer sharing as well as user-level access control if a Windows NT based operating system is available on the network. In contrast, Windows NT-based operating systems offer only user-level access control but integrated with the operating system's own user account security mechanism.

Hardware Support

Drivers

Device drivers in Windows 9x can be virtual device drivers or (starting with Windows 98) WDM drivers. VxDs usually have the filename extension .vxd or .386, whereas WDM compatible drivers usually use the extension .sys. The 32-bit VxD message server (msgsrv32) is a program that is able to load virtual device drivers (VxDs) at startup and then handle communication with the drivers. Additionally, the message server performs several background functions, including loading the Windows shell (such as Explorer.exe or Progman.exe).

Another type of device drivers are .DRV drivers. These drivers are loaded in user-mode, and are commonly used to control devices such as multimedia devices. To provide access to these devices, a dynamic link library is required (such as MMSYSTEM.DLL).

Drivers written for Windows 9x/Windows Me are loaded into the same address space as the kernel. This means that drivers can by accident or design overwrite critical sections of the operating system. Doing this can lead to system crashes, freezes and disk corruption. Faulty operating system drivers were a source of instability for the operating system. Other monolithic and hybrid kernels, like Linux and Windows NT, are also susceptible to malfunctioning drivers impeding the kernel's operation.

Often the software developers of drivers and applications had insufficient experience with creating programs for the 'new' system, thus causing many errors which have been generally described as "system errors" by users, even if the error is not caused by parts of Windows or DOS. Microsoft has repeatedly redesigned the Windows Driver architecture since the release of Windows 95 as a result.

CPU & Bus Technologies

Windows 9x has no native support for hyper-threading, Data Execution Prevention, symmetric multiprocessing or multi-core processors.

Windows 9x has no native support for SATA host bus adapters (and neither did Windows 2000 and Windows XP), or USB drives (except Windows Me). There are, however, many SATA-I controllers for which Windows-98/ME drivers exist. Hardware driver support for Windows 98/ME began to decline in 2005, most notably for motherboard chipsets and video cards.

Early versions of Windows 95 had no support for USB or AGP acceleration. MS-DOS

Windows 95 was able to reduce the role of MS-DOS in Windows much further than had been done in Windows 3.1x and earlier. According to Microsoft, MS-DOS served two purposes in Windows 95: as the boot loader, and as the 16-bit legacy device driver layer.

When Windows 95 started up, MS-DOS loaded, processed CONFIG.SYS, launched COMMAND.COM, ran AUTOEXEC.BAT and finally ran WIN.COM. The WIN.COM program used MS-DOS to load the virtual machine manager, read SYSTEM.INI, load the virtual device drivers, and then turn off any running copies of EMM386 and switch into protected mode. Once in protected mode, the virtual device drivers (VxDs) transferred all state information from MS-DOS to the 32-bit file system manager, and then shut off MS- DOS. These VxDs allow Windows 9x to interact with hardware resources directly, as providing low-level functionalities such as 32-bit disk access and memory management. All future file system operations would get routed to the 32-bit file system manager.

In Windows Me, win.com was no longer executed during the startup process; instead it went directly to execute VMM32.VXD from IO.SYS. The second role of MS-DOS (as the 16-bit legacy device driver layer) was as a backward compatibility tool for running DOS programs in Windows. Many MS-DOS programs and device drivers interacted with DOS in a low-level way; for example, by patching low-level BIOS interrupts such as int 13h, the low-level disk I/O interrupt. When a program issued an int 21h call to access MS-DOS, the call would go first to the 32-bit file system manager, which would attempt to detect this sort of patching. If it detects that the program has tried to hook into DOS, it will jump back into the 16-bit code to let the hook run. A 16-bit driver called IFSMGR.SYS would previously have been loaded by CONFIG.SYS, the job of which was to hook MS-DOS first before the other drivers and programs got a chance, then jump from 16-bit code back into 32-bit code, when the DOS program had finished, to let the 32-bit file system manager continue its work. According to Windows developer Raymond Chen, "MS-DOS was just an extremely elaborate decoy. Any 16-bit drivers and programs would patch or hook what they thought was the real MS-DOS, but which was in reality just a decoy. If the 32-bit file system manager detected that somebody bought the decoy, it told the decoy to quack.

MS-DOS Virtualisation

Windows 9x can run MS-DOS applications within itself using a method called "Virtualization", where an application is run on a "Virtual DOS Machine".

MS-DOS Mode

Windows 95 and Windows 98 also offer regressive support for DOS applications in the form of being able to boot into a native "DOS Mode" (MS-DOS can be booted without booting Windows, not putting the CPU in protected mode). Through Windows 9x's memory managers and other post-DOS improvements, the overall system performance and functionality is improved. This differs from the emulation used in Windows NT- based operating systems. Some very old applications or hardware require "DOS Mode".

Having a command line mode outside of the GUI also offers the ability to fix certain system errors without entering the GUI. For example, if a virus is active in GUI mode it can often be safely removed in DOS mode, by deleting its files, which are usually locked while infected in Windows.

Similarly, corrupted registry files, system files or boot files can be restored from the command line. Windows 95 and Windows 98 can be started from DOS Mode by typing 'WIN' at the command prompt. However, the for Windows 2000, which as a version of Windows NT played a similar role in removing viruses.

Because DOS was not designed for multitasking purposes, Windows versions such as 9x that are DOS-based lack File System security, such as file permissions. Further, if the user uses 16-bit DOS drivers, Windows can become unstable. Hard disk errors often plague the Windows 9x series.

User interface

Users can control a Windows 9x-based system through a command line interface (or CLI), or a graphical user interface (or GUI). For desktop systems, the default mode is usually graphical user interface, where the CLI is available through MS-DOS windows.

The graphical user interface (GUI) runs on a DOS-based layer.

The GDI, which is a part of the Win32 and Win16 subsystems, is also a module that is loaded in user mode, unlike Windows NT where the GDI is loaded in kernel mode.

Alpha compositing and therefore transparency effects, such as fade effects in menus, are not supported by the GDI in Windows 9x.

On desktop machines, Windows Explorer is the default user interface, though a variety of additional Windows shell replacement exist.

Other GUIs include LiteStep, bbLean and Program Manager. The GUI provides a means to control the placement and appearance of individual application windows, and interacts with the Window System. Chapter- 11 Windows XP

Windows XP

Part of the Microsoft Windows family

Screenshot of Windows XP

Developer

Microsoft Corporation

Releases RTM: August 24, 2001 Release date Retail: October 25, 2001

5.1.2600.5512 Service Pack 3 (x86 SP3) (April 21, Current version 2008; 2 years ago)

Source model Closed source, Shared source

License Microsoft-EULA

Kernel type Hybrid

Update method Windows Update

Platform support IA-32, x86-64, IA-64

Support status

Extended Support until April 8, 2014 (only Service Pack 3 x86 and Service Pack 2 x64) Security updates will be provided free of cost. Paid support is still available.

Windows XP is an operating system that was produced by Microsoft for use on personal computers, including home and business desktops, laptops, and media centers. It was first released in August 2001, and is the most popular version of Windows, based on installed user base. The name "XP" is short for "eXPerience."

Windows XP was the successor to both Windows 2000 and Windows Me, and was the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel and architecture. Windows XP was released for retail sale on October 25, 2001, and over 400 million copies were in use in January 2006, according to an estimate in that month by an IDC analyst. It was succeeded by Windows Vista, which was released to volume license customers on November 8, 2006, and worldwide to the general public on January 30, 2007. Direct OEM and retail sales of Windows XP ceased on June 30, 2008. Microsoft continued to sell Windows XP through their System Builders (smaller OEMs who sell assembled computers) program until January 31, 2009. XP may continue to be available as these sources run through their inventory or by purchasing Windows 7 Ultimate, Windows 7 Pro, Windows Vista Ultimate or Windows Vista Business, and then downgrading to Windows XP.

The most common editions of the operating system were Windows XP Home Edition, which was targeted at home users, and Windows XP Professional, which offered additional features such as support for Windows Server domains and two physical processors, and was targeted at power users, business and enterprise clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, view DVD movies, and listen to music. Windows XP Tablet PC Edition was designed to run stylus applications built using the Tablet PC platform.

Windows XP was eventually released for two additional architectures, Windows XP 64- bit Edition for IA-64 (Itanium) processors and Windows XP Professional x64 Edition for x86-64. There is also Windows XP Embedded, a component version of the Windows XP Professional, and editions for specific markets such as Windows XP Starter Edition. By mid 2009, a manufacturer revealed the first Windows XP powered cellular telephone.

The NT-based versions of Windows, which are programmed in C, C++, and assembly, are known for their improved stability and efficiency over the 9x versions of Microsoft Windows. Windows XP presented a significantly redesigned graphical user interface, a change Microsoft promoted as more user-friendly than previous versions of Windows. A new software management facility called Side-by-Side Assembly was introduced to ameliorate the "DLL hell" that plagues 9x versions of Windows. It is also the first version of Windows to use product activation to combat illegal copying. Windows XP had also been criticized by some users for security vulnerabilities, tight integration of applications such as Internet Explorer 6 and Windows Media Player, and for aspects of its default user interface. Later versions with Service Pack 2, Service Pack 3, and Internet Explorer 8 addressed some of these concerns.

During development, the project was codenamed "Whistler", after Whistler, British Columbia, as many Microsoft employees skied at the Whistler-Blackcomb ski resort.

According to web analytics data generated by W3Schools, as of November 2010, Windows XP is the most widely used operating system for accessing the Internet in the world with a 47% market share, having peaked at 76.1% in January 2007.

User interface Windows XP themes

Default Blue (Luna)

Windows Classic

XP Media Center

The new start menu designin the "Energy blue" theme

The "task grouping" feature introduced in Windows XP

Windows XP featured a new task-based graphical user interface. The Start menu and Taskbar were updated and many visual effects were added, including:

• A translucent blue selection rectangle in Explorer • Drop shadows for icon labels on the desktop • Task-based sidebars in Explorer windows ("common tasks") • The ability to group the taskbar buttons of the windows of one application into one button • The ability to lock the taskbar and other toolbars to prevent accidental changes • The highlighting of recently added programs on the Start menu • Shadows under menus (Windows 2000 had shadows under mouse pointers, but not menus)

Windows XP analyzed the performance impact of visual effects and uses this to determine whether to enable them, so as to prevent the new functionality from consuming excessive additional processing overhead. Users can further customize these settings. Some effects, such as alpha compositing (transparency and fading), are handled entirely by many newer video cards. However, if the video card is not capable of hardware alpha blending, performance can be substantially hurt, and Microsoft recommends the feature should be turned off manually. Windows XP added the ability for Windows to use "Visual Styles" to change the user interface. However, visual styles must be cryptographically signed by Microsoft to run. Luna is the name of the new visual style that ships with Windows XP, and is enabled by default for machines with more than 64 MiB of RAM. Luna refers only to one particular visual style, not to all of the new user interface features of Windows XP as a whole. Some users "patch" the uxtheme.dll file that restricts the ability to use visual styles, created by the general public or the user, on Windows XP.

In addition to the included Windows XP themes, there is one previously unreleased theme with a dark blue taskbar and window bars similar to Windows Vista titled "Royale Noir" available for download, albeit unofficially. Microsoft officially released a modified version of this theme as the "Zune" theme, to celebrate the launch of its Zune portable media player in November 2006. The differences are only visual with a new glassy look along with a black taskbar instead of dark blue and an orange start button instead of green. Additionally, the Media Center "Energy Blue" theme, which was included in the Media Center editions, is also available to download for use on all Windows XP editions.

The default wallpaper, Bliss, is a BMP photograph of a landscape in the Napa Valley outside Napa, California, with rolling green hills and a blue sky with stratocumulus and cirrus clouds.

The Windows 2000 "classic" interface can be used instead if preferred. Several third party utilities exist that provide hundreds of different visual styles.

New and updated features

Windows XP introduced several new features to the Windows line, including:

• GDI+ graphics subsystem • Start Menu and Taskbar improvements • A number of new features in Windows Explorer • Faster start-up, logon and logoff and hibernation sequences. • The ability to discard a newer device driver in favor of the previous one (known as driver rollback), should a driver upgrade not produce desirable results. • A new, arguably more user-friendly interface, including the framework for developing themes for the desktop environment • Fast user switching, which allows a user to save the current state and open applications of their desktop and allow another user to log on without losing that information • The ClearType font rendering mechanism, which is designed to improve text readability on liquid crystal display (LCD) and similar monitors • Remote Desktop functionality, which allows users to connect to a computer running Windows XP Pro from across a network or the Internet and access their applications, files, printers, and devices . • Support for most DSL modems and IEEE 802.11 connections, as well as networking over FireWire, and Bluetooth. • Improved application compatibility compared to Windows 2000

Editions

Diagram representing the main editions of Windows XP. It is based on the category of the edition (grey) and codebase (black arrow).

The two major editions are Windows XP Home Edition, designed for home users, and Windows XP Professional, designed for business and power-users. XP Professional contains advanced features that the average home user would not use. However, these features are not necessarily missing from XP Home. They are simply disabled, but are there and can become functional. These releases were made available at retail outlets that sell computer software, and were preinstalled on computers sold by major computer manufacturers. As of mid-2008, both editions continue to be sold. A third edition, called Windows XP Media Center Edition was introduced in 2002 and was updated every year until 2006 to incorporate new digital media, broadcast television and Media Center Extender capabilities. Unlike the Home and Professional edition, it was never made available for retail purchase, and was typically either sold through OEM channels, or was preinstalled on computers that were typically marketed as "media center PCs". Two different 64-bit editions were made available, one designed specifically for Itanium- based workstations, which was introduced in 2001 around the same time as the Home and Professional editions, but was discontinued a few years later when vendors of Itanium hardware stopped selling workstation-class machines due to low sales. The other, called Windows XP Professional x64 Edition, supports the x86-64 extension. x86-64 was implemented first by AMD as "AMD64", found in AMD's Opteron and Athlon 64 chips, and later implemented by Intel as "Intel 64" (formerly known as IA-32e and EM64T), found in Intel's Pentium 4 and later chips.

Windows XP Tablet PC Edition was produced for a class of specially designed notebook/laptop computers called tablet PCs. It is compatible with a pen-sensitive screen, supporting handwritten notes and portrait-oriented screens.

Microsoft also released Windows XP Embedded, an edition for specific consumer electronics, set-top boxes, kiosks/ATMs, medical devices, arcade video games, point-of- sale terminals, and Voice over Internet Protocol (VoIP) components. In July 2006, Microsoft released Windows Fundamentals for Legacy PCs, a thin client version of Windows XP Embedded which targets older machines (as early as the original Pentium). It is only available to Software Assurance customers. It is intended for corporate customers who would like to upgrade to Windows XP to take advantage of its security and management capabilities, but can't afford to purchase new hardware.

Editions for specific markets

Windows XP Starter Edition is a lower-cost edition of Windows XP available in Thailand, Indonesia, Philippines, Russia, India, Colombia, Brazil, Argentina, Peru, Bolivia, Chile, Mexico, Ecuador, Uruguay and Venezuela. It is similar to Windows XP Home, but is limited to low-end hardware, can only run 3 programs at a time, and has some other features either removed or disabled by default. Each country's edition is also customized for that country, including desktop backgrounds of popular locations, localized help features for those who may not speak English, and other default settings designed for easier use than typical Windows XP installations. The Malaysian version, for example, contains a desktop background of the Kuala Lumpur skyline.

In March 2004, the European Commission fined Microsoft €497 million (US$603 million) and ordered the company to provide a version of Windows without Windows Media Player. The Commission concluded that Microsoft "broke European Union competition law by leveraging its near monopoly in the market for PC operating systems onto the markets for work group server operating systems and for media players". After unsuccessful appeals in 2004 and 2005, Microsoft reached an agreement with the Commission where it would release a court-compliant version, Windows XP Edition N. This version does not include the company's Windows Media Player but instead encourages users to pick and download their own media player. Microsoft wanted to call this version Reduced Media Edition, but EU regulators objected and suggested the Edition N name, with the N signifying "not with Media Player" for both Home and Professional editions of Windows XP. Because it is sold at the same price as the version with Windows Media Player included, Dell, Hewlett-Packard, Lenovo and Fujitsu Siemens have chosen not to stock the product. However, Dell did offer the operating system for a short time. Consumer interest has been low, with roughly 1,500 units shipped to OEMs, and no reported sales to consumers.

In December 2005, the Korean Fair Trade Commission ordered Microsoft to make available editions of Windows XP and Windows Server 2003 that do not contain Windows Media Player or . Like the European Commission decision, this decision was based on the grounds that Microsoft had abused its dominant position in the market to push other products onto consumers. Unlike that decision, however, Microsoft was also forced to withdraw the non-compliant versions of Windows from the South Korean market. This decision resulted in Microsoft's releasing "K" and "KN" variants of the Home and Professional editions in August 2006.

That same year, Microsoft also released two additional editions of Windows XP Home Edition directed towards subscription-based and pay-as-you-go pricing models. These editions, released as part of Microsoft's FlexGo initiative, are used in conjunction with a hardware component to enforce time limitations on the usage of Windows. Its target market is emerging economies such as Brazil and Vietnam.

Languages

Windows XP was available in many languages. In addition, MUI packs and Language Interface Packs translating the user interface were also available for certain languages.

ATMs and Vendors

Automated teller machine (ATM) vendors Wincor Nixdorf, NCR Corporation and Diebold Incorporated have all adopted Microsoft Windows XP as their migration path from OS/2. Wincor Nixdorf, who has been pushing for standardization for many years, began shipping ATMs with Windows when they first arrived on the scene.

Diebold initially shipped XP Home Edition exclusively, but, following extensive pressure from customer banks to support a common operating system, switched to support XP Professional to match their primary competitor, NCR Corporation and Wincor Nixdorf.

Redbox DVD Vending machines run a modified version of XP designed for the fullscreen User Interface of the Vending Touchscreen and the DVD vending itself.

Service packs

Microsoft occasionally releases service packs for its Windows operating systems to fix problems and add features. Each service pack is a superset of all previous service packs and patches so that only the latest service pack needs to be installed, and also includes new revisions. However if you still have the earliest version of Windows XP on Retail CD (without any service packs included), you will need to install SP1a or SP2, before SP3 can be installed. Older service packs need not be manually removed before application of the most recent one. Windows Update "normally" takes care of automatically removing unnecessary files.

The service pack details below only apply to the 32-bit editions. Windows XP Professional x64 Edition was based on Windows Server 2003 Service Pack 1 and claimed to be "SP1" in system properties from the initial release. It is updated by the same service packs and hotfixes as the x64 edition of Windows Server 2003.

Service Pack 1

Set Program Access and Defaults was added in Service Pack 1

Service Pack 1 (SP1) for Windows XP was released on September 9, 2002. It contains post-RTM security fixes and hot-fixes, compatibility updates, optional .NET Framework support, enabling technologies for new devices such as Tablet PCs, and a new Windows Messenger 4.7 version. The most notable new features were USB 2.0 support and a Set Program Access and Defaults utility that aimed at hiding various middleware products. Users can control the default application for activities such as web browsing and instant messaging, as well as hide access to some of Microsoft's bundled programs. This utility was first brought into the older Windows 2000 operating system with its Service Pack 3. This Service Pack supported SATA and hard drives that were larger than 137GB (48-bit LBA support) by default. The Microsoft Java Virtual Machine, which was not in the RTM version, appeared in this Service Pack. Support for IPv6 was also introduced in this Service Pack.

On February 3, 2003, Microsoft released Service Pack 1a (SP1a). This release removed Microsoft's Java virtual machine as a result of a lawsuit with Sun Microsystems.

Service Pack 2

Windows Security Center was added in Service Pack 2

Service Pack 2 (SP2) was released on August 25, 2004, with an emphasis on security. Unlike the previous service pack, SP2 added new functionality to Windows XP, such as WPA encryption compatibility and improved Wi-Fi support (with a wizard utility), a pop-up ad blocker for Internet Explorer 6, and Bluetooth support. The new welcome screen during the kernel boot removes the subtitles "Professional", "Home Edition" and "Embedded" since Microsoft introduced new Windows XP editions prior to the release of SP2. The green loading bar in Home Edition and the yellow one in Embedded were replaced with the blue bar, seen in Professional and other versions of Windows XP, making the boot-screen of operating systems resemble each other. Colors in other areas, such as Control Panel and the Help and Support tool, remained as before.

Service Pack 2 also added new security enhancements (codenamed "Springboard"), which included a major revision to the included firewall that was renamed to and became enabled by default, Data Execution Prevention, which can be weakly emulated, gains hardware support in the NX bit that can stop some forms of buffer overflow attacks. Also raw socket support is removed (which supposedly limits the damage done by zombie machines). Additionally, security-related improvements were made to e-mail and web browsing. Windows XP Service Pack 2 includes the Windows Security Center, which provides a general overview of security on the system, including the state of antivirus software, Windows Update, and the new Windows Firewall. Third- party anti-virus and firewall applications can interface with the new Security Center.

Service Pack 2b

In August 2006, Microsoft released updated installation media for Windows XP SP2 and Windows Server 2003 SP1 to contain a patch that requires ActiveX controls to require manual activation in accordance with a patent held by Eolas. Since then, the technology was licensed by Microsoft, and Service Pack 3 and later versions do not include this update.

Service Pack 2c

On August 10, 2007, Microsoft announced a minor update to Service Pack 2, called Service Pack 2c (SP2c). The update fixes the issue of the diminishing number of available product keys for Windows XP. This update was only available to system builders from their distributors in Windows XP Professional and Windows XP Professional N operating systems. SP2c was released in September 2007.

Service Pack 3

Windows XP Service Pack 3 (SP3) was released to manufacturing on April 21, 2008, and to the public via both the Microsoft Download Center and Windows Update on May 6, 2008.

It began being automatically pushed out to Automatic Update users on July 10, 2008. A feature set overview which details new features available separately as standalone updates to Windows XP, as well as backported features from Windows Vista has been posted by Microsoft. A total of 1,174 fixes have been included in SP3. Service Pack 3 can be installed on systems with Internet Explorer versions 6, 7 or 8. Internet Explorer 7 and 8 are not included as part of SP3. New features in Service Pack 3

• Turns black hole router detection on by default • Network Access Protection client • support for IEEE 802.1X authentication for wired network adapters. • Credentials Security Service Provider • Descriptive Security options in Group Policy/Local Security Policy user interface • An updated version of the Microsoft Enhanced Cryptographic Provider Module (RSAENH) that is FIPS 140-2 certified (SHA-256, SHA-384 and SHA-512 algorithms) • Installing without requiring a product key during setup for retail and OEM versions

Previously released updates

Service Pack 3 also incorporated several previously released key updates for Windows XP, which were not included up to SP2 including:

• Windows Imaging Component • IPSec Simple Policy Update for simplified creation and maintenance of IPSec filters • Background Intelligent Transfer Service (BITS) 2.5 • MSXML 6.0 SP2 and XMLLite • Microsoft Management Console 3.0 • Credential Roaming service (Digital Identity Management Service) update • Remote Desktop Protocol 6.1 • Peer Name Resolution Protocol 2.1 • Network Diagnostics update • WPA2 Update (KB893357) • Windows Script 5.7 • Windows Installer 3.1 v2

Slipstreamed retail and OEM versions of Windows XP with SP3 can be installed and run with full functionality for 30 days without a product key, after which time the user will be prompted to enter a valid key and activate the installation. Volume license key (VLK) versions still require entering a product key before beginning installation.

Windows XP Service Pack 3 is a cumulative update of all previous service packs for XP. The service pack installer checks HKLM\SYSTEM\CurrentControlSet\Control\Windows\CSDVersion registry key to see if has a value greater than or equal to 0x100, and if it does it will allow the update to proceed. Otherwise it will prompt to install either XP SP1 or SP2. Since SP1 is no longer available for full download, it would need to be downloaded using Windows Update. The other option is to manually change the registry key, in essence fooling the installer into thinking SP1 is already installed. However, it is possible to slipstream SP3 into the Windows XP setup files at any service pack level—including the original RTM version—without any errors or issues. Slipstreaming SP3 into Windows XP Media Center Edition 2005 is not supported.

Service Pack 3 contains updates to the operating system components of Windows XP Media Center Edition (MCE) and Windows XP Tablet PC Edition, and security updates for .NET Framework version 1.0, which is included in these Windows XP SKUs. However, it does not include update rollups for the application in Windows XP MCE 2005. SP3 also omits security updates for Windows Media Player 10, although the player is included in Windows XP MCE 2005. The Address Bar DeskBand on the Taskbar is no longer included due to legal restrictions. It also removed the Energy Star logo from the ScreenSaver tab of the Display properties, leaving a very noticeable blank space next to the link to enter the Power Management control panel.

Physical memory limits

Maximum limits on physical memory (RAM) that Windows XP can address vary depending on both the Windows version and between 32-bit and 64-bit versions. The following table specifies the maximum physical memory limits supported:

Physical memory limits for Windows XP versions Version Limit in 32-bit Windows Limit in 64-bit Windows Windows XP Professional 4 GB 128GB Windows XP Home Edition 4 GB N/A Windows XP Media Center Edition 4 GB N/A Windows XP Tablet PC Edition 4 GB N/A Windows XP Starter Edition 512 MB N/A

Support lifecycle

Support for Windows XP without a service pack ended on September 30, 2004 and support for Windows XP Service Pack 1 and 1a ended on October 10, 2006.

Windows XP Service Pack 2 was retired on July 13, 2010, almost six years after its general availability. In accordance with Microsoft's posted timetable, the company stopped general licensing of Windows XP to OEMs and terminated retail sales of the operating system on June 30, 2008, 17 months after the release of Windows Vista. However, an exception was announced on April 3, 2008, for OEMs installing to ultra low-cost PCs (ULCPCs) until one year after the availability of Windows 7 (October 22, 2010)

On April 14, 2009, Windows XP and its family of operating systems were moved from Mainstream Support to the Extended Support phase as it marks the progression of the legacy operating system through the Microsoft Support Lifecycle Policy. During the Extended Support Phase, Microsoft will continue to provide security updates every month for Windows XP; however, free technical support, warranty claims and design changes are no longer being offered.

On April 8, 2014, all Windows XP support, including security updates and security- related hotfixes, will be terminated.

Criticism

Security issues

Windows XP has been criticized for its susceptibility to malware, computer viruses, trojan horses, and computer worms. Security issues are compounded by the fact that users, by default, receive an administrator account that provides unrestricted access to the underpinnings of the system. If the administrator's account is broken into, there is no limit to the control that can be asserted over the compromised PC.

Windows, with its large market share, has historically been a tempting target for virus creators. Security holes are often invisible until they are exploited, making preemptive action difficult. Microsoft has stated that the release of patches to fix security holes is often what causes the spread of exploits against those very same holes. Hackers exploit these holes by figuring out what problems the patches fix, and then proceed to launch attacks against unpatched systems. Microsoft recommends that all systems have automatic updates turned on to prevent a system from being attacked by an unpatched bug, but some business IT departments need to test updates before deployment across systems to predict compatibility issues with custom software and infrastructure. This deployment turn-around time also lengthens the time that systems are left unsecured in the event of a released software exploit.

When Windows XP was released in 2001, it came with Internet Explorer 6, which is now insecure and outdated. Since February 2010, Microsoft has urged all users to upgrade to Internet Explorer 8, which has better security.

Integration of operating system features

In light of the United States v. Microsoft case which resulted in Microsoft being found liable for abusing its operating system monopoly to overwhelm competition in other markets, Windows XP has drawn fire for integrating user applications such as Windows Media Player and Windows Messenger into the operating system, as well as for its close ties to the .NET Passport (now Windows Live ID) service.

Backward compatibility

Migrating from Windows 9x to XP can be an issue for users dependent upon MS-DOS. Although XP comes with the ability to run DOS programs in a virtual DOS machine, it still has trouble running many old DOS programs. This is largely because it is a Windows NT system and does not use DOS as a base OS, and that the Windows NT architecture is different from Windows 9x. Some DOS programs that cannot run natively on XP, notably programs that rely on direct access to hardware, can be run in emulators, such as DOSBox or virtual machines, like VMware, Virtual PC, or VirtualBox. This also applies to programs that only require direct access to certain common emulated hardware components, like memory, keyboard, and serial ports.

Product activation and verification

Product activation

In an attempt to reduce piracy, Windows XP introduced product activation. Activation required the computer or the user to activate with Microsoft (either online or over the phone) within a certain amount of time in order to continue using the operating system. If the user's computer system ever changes — for example, if two or more relevant components of the computer itself are upgraded — Windows will return to the unactivated state and will need to be activated again within a defined grace period. If a user tried to reactivate too frequently, the system will refuse to activate online. The user must then contact Microsoft by telephone to obtain a new activation code.

However, activation only applied to retail and "system builder" (intended for use by small local PC builders) copies of Windows. "Royalty OEM" (used by large PC vendors) copies are instead locked to a special signature in the machine's BIOS (and will demand activation if moved to a system whose motherboard does not have the signature) and volume license copies do not require activation at all. Predictably, this led to pirates simply using volume license copies with volume license keys that were widely distributed on the Internet.

Product key testing

In addition to activation, Windows XP service packs will refuse to install on Windows XP systems with product keys known to be widely used in unauthorized installations. These product keys are either intended for use with one copy (for retail and system builder), for one OEM (for BIOS locked copies) or to one company (for volume license copies) and are included with the product. However a number of volume licence product keys (which as mentioned above avoid the need for activation) were posted on the Internet and were then used for a large number of unauthorized installations. The service packs contain a list of these keys and will not update copies of Windows XP that use them.

Microsoft developed a new key verification engine for Windows XP Service Pack 2 that could detect illicit keys, even those that had never been used before. After an outcry from security consultants who feared that denying security updates to illegal installations of Windows XP would have wide-ranging consequences even for legal owners, Microsoft elected to disable the new key verification engine. Service Pack 2 only checks for the same small list of commonly used keys as Service Pack 1. This means that while Service Pack 2 will not install on copies of Windows XP which use the older set of copied keys, those who use keys which have been posted more recently may be able to update their systems.

Windows Genuine Advantage

A Windows Genuine Advantage notification indicating a failed validation

To try to curb piracy based on leaked or generated volume license keys, Microsoft introduced Windows Genuine Advantage (WGA). WGA comprises two parts, a verification tool which must be used to get certain downloads from Microsoft and a user notification system. WGA for Windows was followed by verification systems for Internet Explorer 7, Windows Media Player 11, Windows Defender, Microsoft Office 2007 and certain updates. In late 2007, Microsoft removed the WGA verification from the installer for Internet Explorer 7 saying that the purpose of the change was to make IE7 available to all Windows users.

If the license key is judged not genuine, it displays a nag screen at regular intervals asking the user to buy a license from Microsoft. In addition, the user's access to Microsoft Update is restricted to critical security updates, and as such, new versions of enhancements and other Microsoft products will no longer be able to be downloaded or installed.

On August 26, 2008, Microsoft released a new WGA activation program that displays a plain black desktop background for computers failing validation. The background can be changed, but reverts after 1 hour.

Common criticisms of WGA have included its description as a "Critical Security Update", causing Automatic Updates to download it without user intervention on default settings, its behavior compared to spyware of "phoning home" to Microsoft every time the computer is connected to the Internet, the failure to inform end users what exactly WGA would do once installed (rectified by a 2006 update), the failure to provide a proper uninstallation method during beta testing (users were given manual removal instructions that did not work with the final build), and its sensitivity to hardware changes which cause repeated need for reactivation in the hands of some developers. Also if the user has no connection to the Internet or a phone, it will be difficult to activate it normally.

Strictly speaking, neither the download nor the install of the Notifications is mandatory; the user can change their Automatic Update settings to allow them to choose what updates may be downloaded for installation. If the update is already downloaded, the user can choose not to accept the supplemental EULA provided for the Notifications. In both cases, the user can also request that the update not be presented again. Newer Critical Security Updates may still be installed with the update hidden. However this setting will only have effect on the existing version of Notifications, so it can appear again as a new version. In 2006, California resident Brian Johnson attempted to bring a class action lawsuit against Microsoft, on grounds that Windows Genuine Advantage Notifications violated the spyware laws in the state; the lawsuit was dismissed in 2010.

License and media types

There are three main types of Windows XP licenses: Retail, Volume (VLK), and Original Equipment Manufacturer (OEM). All three types of licenses are available for Windows XP Professional (32-bit and 64-bit). Windows XP Home Edition is limited to Retail and OEM licenses whereas Windows XP Media Center Edition and Windows XP Tablet PC Edition are exclusively available through VLK and OEM licenses.

Each type of license has a different installation CD. For customized or retail media, there is a small difference on each type of disc that will allow that installation disc to accept only one type of product key.

Only retail and volume licenses include support for end-user installation scenarios from Microsoft. OEM software is preinstalled on systems and is supported by the system manufacturer rather than Microsoft. The price of such software is lower. There are two important restrictions on OEM licenses: Microsoft does not offer technical support, and the license cannot be transferred to another computer. The cost of OEM software products bundled with systems is not disclosed by Microsoft nor by its partners, as each system manufacturer will define its own bundling price.

Microsoft recommends that system manufacturers have their systems tested, for a fee, as part of the Windows Quality Online Services (Winqual) which includes extensive testing so that no component will cause instability in the Windows operating system due to incompatibility with the Windows operating system or with other system components or their respective drivers. Having a system tested and approved will allow the manufacturer to bear the "Certified for Windows" logo sticker on the exterior of the system, and there are additional benefits for having a tested product. This includes the product's being listed on the Windows Marketplace. Because of the fees and extensive requirements, Microsoft acknowledges that smaller system manufacturers may not opt in to the program until they produce computer systems at a modest rate and on recurring designs.

Retail

Retail licenses, those purchased from a retail store in full packaging, are of two sub- types: "Upgrade" and "Full Purchase Product", often abbreviated by Microsoft as FPP. FPP licenses are transferable from one computer to another, provided the previous installation is removed from the old computer. Although upgrade licenses are also transferable, a user must have a previous version of Windows even on the new computer to which they are moving the installation. Retail licenses include installation support for end-users, provided directly by Microsoft.

Volume License

A Volume License is the license given to a software version sold to businesses under a direct purchase agreement with Microsoft, and is sold as an upgrade license only, meaning that a previous license must be available for each new volume license. Volume license versions of Windows XP use a Volume License Key (VLK), which is a product key that does not require Windows Product Activation. The term "Volume License Key" refers to the ability to use one product key for multiple systems, depending on the type of agreement. Since Windows XP Volume License versions do not require product activation, this led to leaked copies of VLK media and product keys from businesses leading to piracy of Windows XP quickly spreading across the Internet upon early release. Beginning with Service Pack 1, Microsoft's active attempts to search out and blacklist known pirated VLK product keys became well known due to the inability to install the service pack on a system with one of the blacklisted keys. Later, this led to the Windows Genuine Advantage program.

Original Equipment Manufacturer (OEM)

Original equipment manufacturer (OEM) licenses are preinstalled on, and sold with, pre- assembled computers from system manufacturers. There are two types of OEM product types — those used for "direct OEMs" (major name brands that buy through a direct contract with Microsoft and produce and brand their own media from a Microsoft "Gold Master Copy" by using an authorized Microsoft duplication partner), and those used for "system builders" (local computer shops that buy generic, unbranded kits through authorized Microsoft distributors). Direct OEM product keys will often not activate with system builder installation media because direct OEMs are now required by Microsoft to pre-activate their copies in the factory using their own internal mechanism before delivery to the customer. It is recommended that system builders also pre-activate their systems before delivery, but this is not mandatory.

OEM installations can be customized using the Microsoft OEM Preinstallation Kit with branding, logos, additional applications, optional services, alternate applications for certain Windows components, Internet Explorer links, and various other customizations. All OEM customers must include support and contact information for the initial installation of Windows because it is the responsibility for the OEM to support the Windows installation, and is not provided by Microsoft to the end-user. Direct OEMs must create their own media, but have the option of creating their own custom recovery solution, which may or may not be similar to a generic installation. Direct OEMs may provide a recovery partition on the hard drive as the custom recovery solution rather than providing disc-based media with the computer.

Some end-users have found this to be a troublesome option, because in the event of an out-of-warranty hard drive failure, they may not have access to any installation media in order to reinstall Windows onto a new hard drive. System builders are not allowed the option to create a custom recovery CD/DVD media. The only deliverable media available for a system builder to give to the end-user is the unbranded OEM system builder hologram media kit. Because of this, when end-users reformat their hard drives and re- install from the installation media, they lose all the custom branding and support information that the system builder would have included.

As a supplemental recovery method to a CD/DVD-based installation, a system builder may employ a fully customized recovery solution on the hard drive. Whether utilizing a recovery partition or not, a system builder must still include the original generic OEM system builder hologram CD/DVD media kit. OEM licenses are not transferable from one computer to another. Every computer sold/resold with an OEM license must include all of the original installation media or recovery solution, documentation, Certificate of Authenticity, and product key sticker with the sale. Microsoft requires that all OEM system manufacturers include as part of the configuration the Windows Out-of-Box Experience (OOBE), which is the initial setup wizard encountered the first time Windows boots up. It is also required that value-added resellers (VAR's), retailers, and general resellers not tamper with the OEM's customized OOBE mechanism unless under permission by the OEM, and it is a recommended configuration for systems that are privately resold so that a customer will have a like-new computer experience upon first boot-up.

OEM licenses are to be installed by professional system manufacturers only. Under Microsoft's OEM License Agreement, they are not to be sold to end-users under any circumstance, and are to be preinstalled on a computer using the OEM Preinstallation Kit (OPK) before shipment to the customer, and must include at the very least the manufacturer's support contact information. They are, therefore, designed for installation only on a single computer and are not transferable, even if the original computer is no longer in use. This is not usually an issue for users who purchase new computer systems, because most pre-assembled systems ship with a preinstalled operating system. There are few circumstances where Microsoft will allow the transfer of an OEM license from one non-functioning system to another, but the OEM System Builder License Agreement (SBLA), as well as the OEM End User License Agreement (EULA) do not contain any allowance for this, so it is entirely up to Microsoft's discretion, depending on the situation.

Non-use by end user

In the event that an end user decides that they do not wish to use a preinstalled version of Windows, Microsoft's End User License Agreement (EULA) provides that the software may be returned to the OEM for a refund. Despite refusal of some manufacturers to honor the entitlement, it has been enforced by courts in some countries. System requirements

System requirements for Windows XP Home and Professional editions as follows:

Minimum Recommended Processor 233 MHz* 300 MHz or higher Memory 64 MB RAM** 128 MB RAM or higher Video adapter and monitor Super VGA (800 x 600) or higher resolution 1.5 GB or higher Hard drive disk free space (additional 1.8 GB in Service Pack 2 and additional 900 MB in Service Pack 3) Drives CD-ROM drive or DVD drive Input devices Keyboard. Microsoft Mouse or compatible pointing device Sound Sound card. Speakers or headphones • * Even though this is Microsoft's stated minimum processor speed for Windows XP, it is possible to install and run the operating system on early IA-32 processors such as a P5 Pentium without MMX instructions. Windows XP is not compatible with processors older than Pentium (such as 486) because it requires CMPXCHG8B instructions. • ** For many workloads that involve Web browsing, e-mail, and other activities, 64 MB of RAM will provide [the] user experience equivalent or superior to that of Windows Me running on the same hardware."

Chapter- 12 Windows 7

Windows 7

Part of the Microsoft Windows family

Screenshot of Windows 7 Ultimate Edition

Developer

Microsoft Corporation

Website Official Website

Releases RTM: 22 July 2009 Release date Retail: 22 October 2009

6.1 (build 7600.16385.090713-1255) (22 October 2009; Current version 13 months ago)

Source model Closed source / Shared source

License MS-EULA

Kernel type Hybrid

Update method Windows Update

Platform support IA-32, x86-64

Support status

Mainstream support until January 13, 2015.

Windows 7 is the latest release of Microsoft Windows, a series of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbooks, tablet PCs, and media center PCs. Windows 7 was released to manufacturing on July 22, 2009, and reached general retail availability on October 22, 2009, less than three years after the release of its predecessor, Windows Vista. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time.

Unlike its predecessor, Windows Vista, which introduced a large number of new features, Windows 7 was intended to be a more focused, incremental upgrade to the Windows line, with the goal of being compatible with applications and hardware which Windows Vista was not at the time. Presentations given by Microsoft in 2008 focused on multi-touch support, a redesigned Windows shell with a new taskbar, referred to as the Superbar, a home networking system called HomeGroup, and performance improvements. Some standard applications that have been included with prior releases of Microsoft Windows, including Windows Calendar, Windows Mail, Windows Movie Maker, and , are not included in Windows 7; most are instead offered separately at no charge as part of the Windows Live Essentials suite.

Development

Originally, a version of Windows codenamed Blackcomb was planned as the successor to Windows XP (codename Whistler) and Windows Server 2003. Major features were planned for Blackcomb, including an emphasis on searching and querying data and an advanced storage system named WinFS to enable such scenarios. However, an interim, minor release, codenamed "Longhorn," was announced for 2003, delaying the development of Blackcomb. By the middle of 2003, however, Longhorn had acquired some of the features originally intended for Blackcomb. After three major viruses exploited flaws in Windows operating systems within a short time period in 2003, Microsoft changed its development priorities, putting some of Longhorn's major development work on hold while developing new service packs for Windows XP and Windows Server 2003. Development of Longhorn (Windows Vista) was also restarted, and thus delayed, in August 2004. A number of features were cut from Longhorn.

Blackcomb was renamed Vienna in early 2006 and again Windows 7 in 2007. In 2008, it was announced that Windows 7 would also be the official name of the operating system. There has been some confusion over naming the product Windows 7, while versioning it as 6.1 to indicate its similar build to Vista and increase compatibility with applications that only check major version numbers, similar to Windows 2000 and Windows XP both having 5.x version numbers.

The first external release to select Microsoft partners came in January 2008 with Milestone 1, build 6519. At PDC 2008, Microsoft demonstrated Windows 7 with its reworked taskbar. Copies of Windows 7 build 6801 were distributed at the end of the conference; however, the demonstrated taskbar was disabled in this build.

On December 27, 2008, the Windows 7 Beta was leaked onto the Internet via BitTorrent. According to a performance test by ZDNet, Windows 7 Beta beat both Windows XP and Vista in several key areas; including boot and shutdown time and working with files, such as loading documents. Other areas did not beat XP; including PC Pro benchmarks for typical office activities and video editing, which remain identical to Vista and slower than XP. On January 7, 2009, the 64-bit version of the Windows 7 Beta (build 7000) was leaked onto the web, with some torrents being infected with a trojan. At CES 2009, Microsoft CEO Steve Ballmer announced the Windows 7 Beta, build 7000, had been made available for download to MSDN and TechNet subscribers in the format of an ISO image. The Beta was to be publicly released January 9, 2009, and Microsoft initially planned for the download to be made available to 2.5 million people on this date. However, access to the downloads was delayed because of high traffic. The download limit was also extended, initially until January 24, then again to February 10. People who did not complete downloading the beta had two extra days to complete the download. After February 12, unfinished downloads became unable to complete. Users could still obtain product keys from Microsoft to activate their copies of Windows 7 Beta, which expired on August 1, 2009.

The release candidate, build 7100, became available for MSDN and TechNet subscribers and Connect Program participants on April 30, 2009. On May 5, 2009 it became available to the general public, although it had also been leaked onto the Internet via BitTorrent. The release candidate was available in five languages and expired on June 1, 2010, with shutdowns every two hours starting March 1, 2010. Microsoft stated that Windows 7 would be released to the general public on October 22, 2009. Microsoft released Windows 7 to MSDN and Technet subscribers on August 6, 2009, at 10:00 a.m. PDT. Microsoft announced that Windows 7, along with Windows Server 2008 R2, was released to manufacturing on July 22, 2009. Windows 7 RTM is build 7600.16385, which was compiled on July 13, 2009, and was declared the final RTM build after passing all Microsoft's tests internally.

Windows NT is written in C, C++, and assembly.

Goals

Bill Gates, in an interview with Newsweek, suggested that this version of Windows would be more "user-centric". Gates later said that Windows 7 would also focus on performance improvements. Steven Sinofsky later expanded on this point, explaining in the Engineering Windows 7 blog that the company was using a variety of new tracing tools to measure the performance of many areas of the operating system on an ongoing basis, to help locate inefficient code paths and to help prevent performance regressions.

Senior Vice President Bill Veghte stated that Windows Vista users migrating to Windows 7 would not find the kind of device compatibility issues they encountered migrating from Windows XP. Speaking about Windows 7 on October 16, 2008, Microsoft CEO Steve Ballmer confirmed compatibility between Vista and Windows 7, indicating that Windows 7 would be a refined version of Windows Vista.

Features

New and changed features

The new , which replaces Windows Security Center

When the action center flag is clicked on, it displays a thumbnail with any security issues listed.

Windows 7 includes a number of new features, such as advances in touch and , support for virtual hard disks, improved performance on multi- core processors, improved boot performance, DirectAccess, and kernel improvements. Windows 7 adds support for systems using multiple heterogeneous graphics cards from different vendors (Heterogeneous Multi-adapter), a new version of Windows Media Center, a Gadget for Windows Media Center, improved media features, the XPS Essentials Pack and Windows PowerShell being included, and a redesigned Calculator with multiline capabilities including Programmer and Statistics modes along with unit conversion. Many new items have been added to the Control Panel, including ClearType Text Tuner, Display Color Calibration Wizard, Gadgets, Recovery, Troubleshooting, Workspaces Center, Location and Other Sensors, Credential Manager, Biometric Devices, System Icons, and Display. Windows Security Center has been renamed to Windows Action Center (Windows Health Center and Windows Solution Center in earlier builds), which encompasses both of the computer. Readyboost on 32bit editions now supports up to 256 Gigabytes of extra allocation. The default setting for User Account Control in Windows 7 has been criticized for allowing untrusted software to be launched with elevated privileges without a prompt by exploiting a trusted application. Microsoft's Windows kernel engineer Mark Russinovich acknowledged the problem, but noted that malware can also compromise a system when users agree to a prompt. Windows 7 also supports images in the RAW image format through the addition of Windows Imaging Component-enabled image decoders, which enables raw image thumbnails, previewing and metadata display in Windows Explorer, plus full-size viewing and slideshows in and Window Media Center.

The taskbar has seen the biggest visual changes, where the Quick Launch toolbar has been replaced with the "Superbar" allowing applications to be pinned to the taskbar. Buttons for pinned applications are integrated with the task buttons. These buttons also enable the Jump Lists feature to allow easy access to common tasks. The revamped taskbar also allows the reordering of taskbar buttons. To the far right of the system clock is a small rectangular button that serves as the Show desktop icon. This button is part of the new feature in Windows 7 called Aero Peek. Hovering over this button makes all visible windows transparent for a quick look at the desktop. In touch-enabled displays such as touch screens, tablet PCs, etc., this button is slightly wider to accommodate being pressed with a finger. Clicking this button minimizes all windows, and clicking it a second time restores them. Additionally, there is a feature named Aero Snap, that automatically maximizes a window when it is dragged to the top of the screen. Dragging windows to the left/right edges of the screen allows users to snap documents or files on either side of the screen for comparison between windows. When a user moves windows that were maximized using Aero Snap, the system restores their previous state automatically. This functionality is also accomplished with keyboard shortcuts. Unlike in Windows Vista, window borders and the taskbar do not turn opaque when a window is maximized with applied. Instead, they remain translucent.

The Windows 7 taskbar

For developers, Windows 7 includes a new networking API with support for building SOAP-based web services in native code (as opposed to .NET-based WCF web services), new features to shorten application install times, reduced UAC prompts, simplified development of installation packages, and improved globalization support through a new Extended Linguistic Services API. At WinHEC 2008 Microsoft announced that color depths of 30-bit and 48-bit would be supported in Windows 7 along with the wide color gamut scRGB (which for HDMI 1.3 can be converted and output as xvYCC). The video modes supported in Windows 7 are 16-bit sRGB, 24-bit sRGB, 30-bit sRGB, 30-bit with extended color gamut sRGB, and 48-bit scRGB. Microsoft has also implemented better support for solid-state drives, including the new TRIM command, and Windows 7 is able to identify a solid-state drive uniquely. Microsoft is planning to support USB 3.0 in a subsequent patch, support not being included in the initial release due to delays in the finalization of the standard.

Internet Spades, Internet Backgammon and Internet Checkers, which were removed from Windows Vista, were restored in Windows 7. Windows 7 includes Internet Explorer 8 and Windows Media Player 12.

Users are also able to disable many more Windows components than was possible in Windows Vista. New additions to this list of components include Internet Explorer, Windows Media Player, Windows Media Center, , and the Windows Gadget Platform. Windows 7 includes 13 additional sound schemes, titled Afternoon, Calligraphy, Characters, Cityscape, Delta, Festival, Garden, Heritage, Landscape, Quirky, Raga, Savanna, and Sonata. A new version of Microsoft Virtual PC, newly renamed as Windows Virtual PC was made available for Windows 7 Professional, Enterprise, and Ultimate editions. It allows multiple Windows environments, including Windows XP Mode, to run on the same machine. Windows XP Mode runs Windows XP in a virtual machine and redirects displayed applications running in Windows XP to the Windows 7 desktop. Furthermore, Windows 7 supports the mounting of a virtual hard disk (VHD) as a normal data storage, and the bootloader delivered with Windows 7 can boot the Windows system from a VHD, however, this is only available in the Enterprise and Ultimate editions. The Remote Desktop Protocol (RDP) of Windows 7 is also enhanced to support real-time multimedia application including video playback and 3D games, thus allowing use of DirectX 10 in remote desktop environments. The three application limit, previously present in the Windows Vista Starter Edition, has been removed from Windows 7.

Removed features

A number of capabilities and certain programs that were a part of Windows Vista are no longer present or have been changed, resulting in the removal of certain functionalities. These include the classic Start Menu user interface, some taskbar features, Windows Explorer features, Windows Media Player features, and InkBall. Four applications bundled with Windows Vista — Windows Photo Gallery, Windows Movie Maker, Windows Calendar and Windows Mail — are not included with Windows 7, but applications with mostly similar functionality are instead available for free in a separate package called Windows Live Essentials which can be found on the Microsoft website. Although Windows Ultimate Extras was removed, many of the extras can be installed. Most popular extras were Microsoft Texas Hold 'em, Microsoft Tinker, and Windows DreamScene. InkBall may also be installed into Windows 7.

Antitrust regulatory attention

As with other Microsoft operating systems, Windows 7 is being studied by United States federal regulators who oversee the company's operations following the 2001 United States v. Microsoft settlement. According to status reports filed, the three-member panel began assessing prototypes of the new operating system in February 2008. Michael Gartenberg, an analyst at Jupiter Research said that, "[Microsoft's] challenge for Windows 7 will be how can they continue to add features that consumers will want that also don't run afoul of regulators."

Europe

In order to comply with European antitrust regulations, Microsoft has proposed the use of a "ballot" screen, allowing users to download a competing browser, thus removing the need for a version of Windows completely without Internet Explorer, as previously planned. In response to criticism involving Windows 7 E and concerns from manufacturers about possible consumer confusion if a version of Windows 7 with Internet Explorer were shipped later after one without Internet Explorer, Microsoft announced that it would scrap the separate version for Europe and ship the standard upgrade and full packages worldwide.

As with the previous version of Windows, an N version, which does not come with Windows Media Player, has been released in Europe, but only for sale directly from Microsoft sales websites and selected others. Reception

In July 2009, in only eight hours, pre-orders of Windows 7 at Amazon.co.uk surpassed the demand Windows Vista had in its first 17 weeks. It became the highest-grossing pre- order in Amazon's history, surpassing sales of the previous record holder, the seventh Harry Potter book. After 36 hours, 64-bit versions of Windows 7 Professional and Ultimate editions sold out in Japan. Two weeks after its release, it was announced that its market share had surpassed that of Snow Leopard, released two months previously as the most recent update to Apple's Mac OS X operating system. According to Net Applications, Windows 7 reached a 4% market share in less than three weeks. In comparison, it took Windows Vista seven months to reach the same mark. As of March 4, 2010, Microsoft announced that it had sold more than 90 million Windows 7 licenses. On April 23, 2010, Windows 7 has sold more than 100 million copies in six months which made it Microsoft's fastest selling operating system. As of June 23, 2010, Windows 7 has sold 150 million copies which made it the fastest selling operating system in history with seven copies sold every second. Based on worldwide data taken during June 2010 from Windows Update 46% of Windows 7 PCs run the 64-bit edition of Windows 7. According to Stephen Baker of the NPD Group during April 2010 in the United States 77% of PCs sold at retail were pre-installed with the 64-bit edition of Windows 7. As of July 22, 2010, Windows 7 had sold 175 million copies. On October 21, 2010, Microsoft announced that more than 240 million copies of Windows 7 had been sold.

Reviews of Windows 7 were extremely positive, praising its usability when compared to its predecessor, Windows Vista. CNET gave Windows 7 Home Premium a rating of 4.5 out of 5 stars, stating that it "is more than what Vista should have been, [and] it's where Microsoft needed to go". PC Magazine rated it a 4 out of 5 saying that Windows 7 is a "big improvement" over Windows Vista, with fewer compatibility problems, a retooled taskbar, simpler home networking and faster start-up. Maximum PC gave Windows 7 a rating of 9 out of 10 and called Windows 7 a "massive leap forward" in usability and security, and praised the new Taskbar as "worth the price of admission alone". PC World called Windows 7 a "worthy successor" to Windows XP and said that speed benchmarks showed Windows 7 to be slightly faster than Windows Vista. PC World also named Windows 7 one of the best products of the year. In its review of Windows 7, Engadget said that Microsoft has taken a "strong step forward" with Windows 7 and reported that speed is one of Windows 7's major selling points particularly for the netbook sets. LAPTOP Magazine gave Windows 7 a rating of 4 out of 5 stars and said that Windows 7 makes computing more intuitive, offered better overall performance including a "modest to dramatic" increase in battery life on laptop computers. Techradar gave it a 5 star rating calling it the best version of Windows yet. The New York Times, USA Today, The Wall Street Journal, and The Telegraph also gave Windows 7 favorable reviews.

Some Vista Ultimate users have expressed concerns over Windows 7 pricing and upgrade options. Windows Vista Ultimate users wanting to upgrade from Windows Vista to Windows 7 must either pay $219.99 to upgrade to Windows 7 Ultimate or perform a clean install, which requires them to reinstall all of their programs. Editions

Windows 7 is available in six different editions, but only the Home Premium, Professional, and Ultimate editions are available for retail sale to consumers in most countries. The other editions are aimed at other markets, such as the developing world or enterprise use. Each edition of Windows 7 includes all of the capabilities and features of the edition below it. All editions support the 32-bit (IA-32) processor architecture and all editions except Starter support the 64-bit (x86-64) processor architecture. The installation media is the same for all the consumer editions of Windows 7 that have the same processor architecture, with the license determining the features that are activated, and license upgrades permitting the subsequent unlocking of features without re-installation of the operating system. This is the first time Microsoft has distributed 2 DVDs (1 DVD for IA-32 processor architecture, the other DVD for x86-64 processor architecture) for each edition of Windows 7 (Except for Starter and Home Basic; only in Retail, not OEM; the installation DVD of Windows 7 Home Basic 64-bit edition is not included in the retail packaging but can be obtained from Microsoft.). Users who wish to upgrade to an edition of Windows 7 with more features can then use to purchase the upgrade, and unlock the features of those editions. Some copies of Windows 7 have restrictions, in which it must be distributed, sold, or bought and activated in the geographical region (One of the geographical regions can be either: Southeast Asia; India; or Latin America and the Caribbean) specified in its front cover box.

Microsoft is offering a family pack of Windows 7 Home Premium (in select markets) that allows installation on up to three PCs. The "Family Pack" costs US$259.99 in the United States; it was available at a cost of US$149.99 for some weeks when it was first introduced.

On September 18, 2009, Microsoft said they were to offer temporary student discounts for Windows 7. The offer ran in the US and the United Kingdom, with similar schemes available in Canada, Australia, Korea, Mexico, France and India. Students with a valid .edu or .ac.uk email address could apply for either Windows 7 Home Premium or Professional, priced at $30 or £30.

Windows 7 is also currently available as an embedded version to developers (previously Windows Embedded 2011).

Marketing

The different editions of Windows 7 have been designed and marketed toward people with different needs. Out of the different editions (Starter, Home Basic, Home Premium, Professional, Enterprise, and Ultimate), the Starter edition has been designed and marketed for lower cost notebooks, Home Basic for emerging markets, Home Premium for normal home users, Professional for businesses, Enterprise for larger businesses and corporations, and Ultimate for enthusiasts. Hardware requirements

Recent PCs meeting the minimum hardware requirements or that run Windows 7 may feature this sticker.

Microsoft has published the minimum specifications for a system to run Windows 7. Requirements for the 32-bit version are similar to that of premium editions of Vista, but are higher for 64-bit versions. Microsoft has released an upgrade advisor that determines if a computer is compatible with Windows 7. Although the Nvidia GeForce FX (5xxx) series graphics cards meet the minimum hardware requirement, nVidia has decided not to produce Windows 7 compatible drivers for anything below the GeForce 6 Series.

Minimum hardware requirements for Windows 7 Architecture 32-bit 64-bit Processor 1 GHz x86 processor 1 GHz x86-64 processor Memory (RAM) 1 GB 2 GB DirectX 9 graphics processor with WDDM driver model 1.0 Graphics Card (Not absolutely necessary; only required for Aero) HDD free space 16 GB of free disk space 20 GB of free disk space Optical drive DVD drive (only to install from DVD/CD Media)

Additional requirements to use certain features:

• Windows XP Mode (Professional, Ultimate and Enterprise): Requires an additional 1GB of RAM and additional 15GB of available hard disk space. The requirement for a processor capable of hardware virtualization has been lifted. • Windows Media Center (included in Home Premium, Professional, Ultimate and Enterprise), requires a TV tuner to receive and record TV.

Physical memory limits

Maximum limits on physical memory (RAM) that Windows 7 can address vary depending on both the Windows version and between 32-bit and 64-bit versions. The following table specifies the maximum physical memory limits supported:

Physical memory limits for Windows 7 versions Version Limit in 32-bit Windows Limit in 64-bit Windows Windows 7 Ultimate 4 GB 192 GB Windows 7 Enterprise 4 GB 192 GB Windows 7 Professional 4 GB 192 GB Windows 7 Home Premium 4 GB 16 GB Windows 7 Home Basic 4 GB 8 GB Windows 7 Starter 2 GB N/A

Multi-core processor and multiprocessor limits

The maximum quantity of cores in 1 physical processor of a PC that Windows 7 supports is: 32 for 32-bit, 256 for 64-bit. The maximum quantity of physical processors of a PC that Windows 7 supports is: 2 for Professional, Enterprise, and Ultimate; 1 for Starter, Home Basic, and Home Premium.

Service packs

Windows 7 Service Pack 1 (SP1) was announced on March 18, 2010 and is currently in development. A beta was released on July 12, 2010. Microsoft confirmed that the service pack is to be on a much smaller scale than those released for previous versions of Windows, particularly Windows Vista.

On April 7, 2010, a build of Windows 7 Service Pack 1 dated from March 27, 2010 was leaked onto torrent sites. The leaked service pack has a build number of 6.1.7601.16537.amd64fre.win7.100327-0053 and installation has been reported to be much quicker than service packs for previous versions of Windows.

The latest beta version of Service Pack 1 that was officially released by Microsoft has a version number of "6.1.7601.178".

On October 6, 2010, Softpedia reports that Microsoft released a Release Candidate Escrow of Windows 7 Service Pack 1 build "6.1.7601.17104" only available to Select Testers and close partners of Microsoft.

On October 26, 2010, Microsoft officially released the Release Candidate of the Service Pack 1 for Windows 7. It has a version number of "6.1.7601.17105".

Current official release of Service Pack 1 is slated for the first quarter of 2011, according to its announcement.