This article lists notable commands provided by the MS-DOS disk operating system (DOS), especially as used on an IBM PC compatible computer. Other DOS variants as well as the legacy Windows shell, Command Prompt (cmd.exe), provide many of these commands. Many other DOS variants are informally called DOS, but are not included in the scope of the list. The highly related variant, IBM PC DOS, is included. The list is not intended to be exhaustive, but does include commands covering the various releases.
Each command is implemented either as built-in to the command interpreter, COMMAND.COM, or as an external program. Although prevailing style is to write command names in all caps, the interpreter matches ignoring case.
Commands
APPEND
Sets the path to be searched for data files or displays the current search path.
The APPEND command is similar to the PATH command that tells DOS where to search for program files (files with a .COM, . EXE, or .BAT file name extension).
The command is available in MS-DOS versions 3.2 and later.
ASSIGN
Redirects requests for disk operations on one drive to a different drive. It can also display drive assignments or reset all drive letters to their original assignments.
The command is available in MS-DOS versions 3 through 5 and IBM PC DOS releases 2 through 5. Novell DOS 7 and PC DOS 7.0. Earlier versions of DR-DOS supported this function with the built-in switch command (for numeric choices) or by beginning a command with a question mark.
The command is available in MS-DOS versions 2 and later.
DBLSPACE
A disk compression utility supplied with MS-DOS version 6.0 (released in 1993) and version 6.2.
DRVSPACE
A disk compression utility supplied with MS-DOS version 6.22.
AccessDOS assists persons with disabilities.
FASTHELP
Provides information for MS-DOS commands.
FASTOPEN
Provides accelerated access to frequently-used files and directories.
The command is available in MS-DOS versions 3.3 and later.
The command is available in MS-DOS versions 3 through 5. The opposite can be achieved via the SUBST command.
The command is available in MS-DOS versions 3 through 5. It is available separately for versions 6.2 and later on the Supplemental Disk.
LINK4
Microsoft 8086 Object Linker
LOADFIX
Loads a program above the first 64K of memory, and runs the program. The command is available in MS-DOS versions 5 and later.
LOADHIGH and LH
Loads a program into the upper memory area.
The command is available in MS-DOS versions 5 and later.
MEMMAKER.EXE and SIZER.EXE were developed for Microsoft by Helix Software Company and were eliminated starting in MS-DOS 7 (Windows 95); however, they could be obtained from Microsoft's FTP server as part of the OLDDOS.EXE package, alongside other tools.
PC DOS uses another program called RamBoost to optimize memory, working either with PC DOS's HIMEM/EMM386 or a third-party memory manager. RamBoost was licensed to IBM by Central Point Software.
MIRROR
Saves disk storage information that can be used to recover accidentally erased files.
The command is available in MS-DOS version 5. It is available separately for versions 6.2 and later on Supplemental Disk.
The command is available in MS-DOS versions 3.2 and later and IBM PC DOS releases 1 and later.
The command is available in MS-DOS versions 6 and later. There is another offering, named MWBACKUP, that is GUI-oriented. It was introduced for Windows for Workgroups (3.11).
The MSBACKUP command is available in MS-DOS versions 6 and later. the PC DOS version of this command is QCONFIG. The command appeared first in Word2, and then in Windows 3.10.
MSHERC
A TSR graphics driver supplied with Microsoft QuickC, QuickBASIC, and the C Compiler, to allow use of the Hercules adapter high-resolution graphics capability (720 x 348, 2 colors).
NLSFUNC
Loads extended nationalization and localization support from COUNTRY.SYS, and changed the codepage of drivers and system modules resident in RAM.
In later versions of DR-DOS 6, NLSFUNC relocated itself into the HiMem area, thereby freeing a portion of the nearly invaluable lower 640KiB that constituted the ”conventional” memory available to software.
The command is available in MS-DOS versions 3.3 and later.
It is not included in many DOS versions; typically ones with network stacks will have it as a diagnostic tool.
POWER
Turns power management on and off, reports the status of power management, and sets levels of power conservation. It is an external command.
The command is available in MS-DOS versions 6 and later.
The command is available in MS-DOS versions 1 and later.
SETUP
The command is available in MS-DOS versions 5 and later.
The command is available in MS-DOS versions 2 and later.
The command is available in MS-DOS versions 2 and later.