MS-DOS secret or unknown commands

Updated: 01/31/2019 by Computer Hope
MS-DOS secret commands

Below is a listing of MS-DOS commands that are not listed in any available manual. Many of these commands are useful when using MS-DOS, while some are unknown or appear to do nothing.


Use these commands cautiously, some commands can erase data and some 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 using the dir command, does not work in Windows 95, 98, NT, and 2000.
DIR ... Lists all directories that do not have extensions. In Windows 95 and later, the command lists the contents of the directories previous to the current directory.
DOSKEY /APPEDIT Utilize doskey functions in MS-DOS command utilities such as edlin and debug.
FDISK /MBR Recreates the master boot record. For further information, see: Do you have additional information on fdisk /mbr?
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 /AUTOTEST Formats the hard drive without any prompting.
FORMAT /BACKUP Like /AUTOTEST, but you be prompted 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 Make all directories hidden but still accessible, to get them back SET DIRCMD=
SHARE /NC Unknown
TRUENAME When placed before a file, displays the whole directory that exists.
VER /R Tells you the revision number, and if DOS is in HMA.