The Blue Screen of Death (also known as a stop error, bluescreen, Blue Screen of Doom or BSoD) is an error screen displayed by some operating systems, most notably Microsoft Windows, after encountering a critical system error which can cause the system to shut down, to prevent damage. OS/2 and MS-DOS suffered the Black Screen of Death. Early builds of Windows Vista displayed the Red Screen of Death after a boot loader error. Contents [hide] 1 History 2 Format 3 Windows NT 3.1 Details 3.2 Windows 9x 4 Windows CE 5 Windows 3.1 6 PlayStation Portable 7 Similar screens 7.1 Xbox 7.2 Mac OS X 10.5 Leopard 7.3 Game Boy Advance 7.4 Nintendo DS 7.5 Wii 7.6 Apple IIgs 8 See also 9 References 10 External links History The term "Blue Screen of Death" originated during OS/2 pre-release development activities at Lattice Inc, the makers of an early Windows and OS/2 C compiler. During porting of Lattice's other tools, developers encountered the stop screen when null pointers were dereferenced either in application code or when unexpectedly passed into system API calls. During reviews of progress and feedback to IBM Austin, the developers described the stop screen as the Blue Screen of Death to denote the screen and the finality of the experience.[citation needed] BSoDs have been present in all Windows-based operating systems since Windows 3.1. (See History of Microsoft Windows) BSoDs can be caused by poorly written device drivers or malfunctioning hardware, such as faulty memory, power supply issues, overheating of components, or hardware running beyond its specification limits. In the Windows 9x era, incompatible DLLs or bugs in the operating system kernel could also cause BSoDs. Format Until Windows Server 2012, BSoDs showed white text (CGA color code: 0x0F; HTML color code: #FFFFFF) on a navy blue background (CGA color code: 0x01; HTML color code: #0000AA) with information about current memory values and register values. For visually impaired users, Microsoft has added a utility that allows the user to change a setting in SYSTEM.INI that controls the colors that the BSoD code uses to any of the 16 CGA colors.[citation needed] Doing so requires the edit or addition of the "MessageBackColor=X" and "MessageTextColor=X" lines to the [386enh] section of the SYSTEM.INI, where X is a hexadecimal number from 0 to F corresponding with a color in the CGA 16-color palette. Windows Server 2012 and Windows 8 use a cerulean background instead. (HTML color code: #2067b2) Windows 95, 98 and Me BSoDs use 80×25 text mode. BSoDs of Windows NT family use 80×50 text mode on a 720×400 screen. Windows XP BSoDs uses the Lucida Console font while the Vista BSoD uses the Consolas font. Windows Server 2012 uses Segoe UI and renders the BSoD at native resolution. Windows NT A Blue Screen of Death as seen in Windows XP ReactOS, an attempt at creating a free and open-source implementation of a Windows NT-compatible operating system, also features its own BSoD similar to the Windows NT/XP one In Windows NT family of operating systems, the blue screen of death occurs when the kernel or a driver running in kernel mode encounters an error from which it cannot recover. This is usually caused by an illegal operation being performed. The only safe action the operating system can take in this situation is to restart the computer. As a result, data may be lost, as users are not given an opportunity to save data that has not yet been saved to the hard drive. Blue screens are known as "Stop errors" in the Windows Resource Kit documentation. They are referred to as "bug checks" in the Windows Software development kit and Driver development kit documentation. The text on the error screen contains the code of the error and its symbolic name (e.g. "0x0000001E, KMODE_EXCEPTION_NOT_HANDLED") along with four error-dependent values in parentheses that are there to help software engineers fix the problem that occurred. Depending on the error code, it may display the address where the problem occurred, along with the driver which is loaded at that address. Under Windows NT and 2000, the second and third sections of the screen may contain information on all loaded drivers and a stack dump, respectively. The driver information is in three columns; the first lists the base address of the driver, the second lists the driver's creation date (as a Unix timestamp), and the third lists the name of the driver.[1] By default, Windows will create a memory dump file when a blue screen error occurs. Depending on the OS version, there may be several formats this can be saved in, ranging from a 64kB "minidump" to a "complete dump" which is effectively a copy of the entire contents of physical RAM. The resulting memory dump file may be debugged later, using a kernel debugger. A debugger is necessary to obtain a stack trace, and may be required to ascertain the true cause of the problem; as the information on-screen is limited and thus possibly misleading, it may hide the true source of the error. Microsoft Windows can also be configured to send live debugging information to a kernel debugger running on a separate computer. Windows XP also allows for kernel debugging from the machine that is running the OS. If a blue screen error is encountered while a live kernel debugger is attached to the system, Windows will halt execution and cause the debugger to break in, rather than displaying the BSoD. The debugger can then be used to examine the contents of memory and determine the source of the problem. The Windows debugger is available as a free download from Microsoft.[2] Windows includes a feature that can be used to cause a blue screen manually. To enable it, the user must add a value to the Windows registry (using regedit.exe). After that, a BSoD will appear when the user presses the SCROLL LOCK key twice while holding the right CTRL key.[3] This feature is primarily useful for obtaining a memory dump of the computer while it is in a given state. As such, it is generally used to aid in troubleshooting system hangs. By default, Windows XP is configured to save only a 64kB minidump when it encounters a blue screen, and to then automatically reboot the computer. Because this process happens very quickly, the blue screen may be seen only for an instant or not at all. Users have sometimes noted this as a random reboot rather than a traditional stop error, and are only aware of an issue after Windows reboots and displays a notification that it has recovered from a serious error. This happens only when the computer has a function called "Auto Restart" enabled, which can be disabled in the Control Panel which in turn shows the BSoDs. A BSoD can also be caused by a critical boot loader error, where the operating system is unable to access the boot partition due to incorrect storage drivers, a damaged file system or similar problems. The error code in this situation is STOP 0x0000007B (INACCESSIBLE_BOOT_DEVICE). In such cases, there is no memory dump saved. Since the system is unable to boot from the hard drive in this situation, correction of the problem often requires booting from the Microsoft Windows CD. After booting to the CD, it may be possible to correct the problem by performing a repair install or by using the Recovery Console (with CHKDSK). Blue was chosen because the console colors of DEC Alpha, a platform that runs a version of Windows NT, could not be changed easily.[4] For consistency reasons, blue became the colour for Stop errors on all platforms (alpha/i386/mips/ppc). Another famous instance of a BSoD was at the 2008 Summer Olympics Opening Ceremony. [5] Media reports that Windows XP was used for the ceremony rather than Windows Vista. [6] Another BSOD was displayed through the Beijing 2008's Water Cube projection system.[7] Details Before Windows Server 2012, each BSoD displayed an error name in uppercase (e.g. APC_INDEX_MISMATCH), a hexadecimal error number (e.g. 0x00000001) and four parameters. The last two are shown together in the following format:[8] error code (parameter 1, parameter 2, parameter 3, parameter 4) error name Depending on the error number and its nature, all, some or even none of the parameters contain data pertaining to what went wrong, and/or where it happened. In addition, the error screens showed four paragraphs of general explanation and advice and may have included other technical data such the file name of the culprit and memory addresses. Windows Server 2012 and Windows 8 have dropped all of the above in favor of a concise description and an error name. Technical data may be extracted from Windows Event Log. Windows 9x Windows 9x The blue screen of death frequently occurs in Microsoft's home desktop operating systems Windows 95, 98, and Me. Here it is usually less serious, but much more common. In these operating systems, the BSoD is the main way for virtual device drivers to report errors to the user. It is internally referred to by the name of "_VWIN32_FaultPopup". A Windows 9x/Me BSoD gives the user the option either to restart or continue. However, VxDs do not display BSoDs frivolously — they usually indicate a problem that cannot be fixed without restarting the computer, and hence after a BSoD is displayed the system is usually unstable or unresponsive.