MS-DOS secret and/or unknown commands Below is a listing of MS-DOS commands that are not listed in any available help manual or in the commands syntax or are commonly unknown commands. Many of these commands that are known can be very useful when using MS-DOS, while some of the other commands are unknown and/or appear to do nothing.

Please use these commands cautiously, some of the commands can erase data and/or erase data without warning.

ATTRIB , The command is short for ATTRIB -a -h -r - s *.* (removes all attributes of a file). BACKUP /HP Unknown DIR , This lists all files including hidden files, does not work in Windows 95 / 98 / NT / 2000. DIR ... Lists all directories that do not have extensions. In Windows 95 / Windows 98 will list the contents of the directories previous to the directory currently in. DOSKEY /APPEDIT Utilize doskey functions in MS-DOS command utilities such as edlin and debug. DOSKEY Unknown /COMMAND DOSKEY Unknown /PERMANENT DOSKEY /SCRSIZE Unknown DOSKEY Unknown /XHISTORY FDISK /MBR Recreates the Master Boot Record See CH000175 for additional information. FDISK /PRI See FDISK Page for additional information. FDISK /EXT See FDISK Page for additional information. FDISK /LOG See FDISK Page for additional information. FDISK /Q Prevents fdisk from booting the system automatically after exiting fdisk. FDISK /STATUS Shows you the current status of your hard drives. FORMAT Formats the hard drive without any prompting. /AUTOTEST FORMAT /BACKUP Like /AUTOTEST but it will ask you for a volume label. FORMAT /Z:n Command used with FDISK supporting FAT32, used to specify the cluster size in bytes where n is multiplied by 512. MEM /A or /ALL Adds a line into the MEM command tells the available space in HMA. RESTORE /Y Unknown RESTORE /Z Unknown SET DIRCMD=0 Will make all directories hidden however still accessible, to get them back SET DIRCMD= SHARE /NC Unknown TRUENAME When placed before a file, will display the whole directory in which it exists. VER /R Tells you the Revision and if DOS is in HMA.