Using Dos7 Commands - Introduction


These pages are designed to remind the occasional user of Dos commands just what is on offer. I realize that few people using Windows 95/8 are going to open a DOS window and most of those that do will be pretty familiar with the somewhat similar commands of previous MS-DOS versions. Nevertheless, there are some differences, and Dos can do things that are difficult, if not impossible, in Windows.

The focus of this site is the syntax and use of the commands. Although my initial plans were grandiose, I have found that keeping on top of just this is as much as I can handle. There are several excellent sites covering batch files and a number that offer tutorials/general advice (see links).

I hope to expand this list as time permits, but in the meantime I would be most grateful for any comments, especially with respect to:

  • Mistakes. If I have got something wrong, or have obviously misunderstood how a command should work, PLEASE tell me!
  • Omissions. If I have left out a switch (documented or not), again, please let me know.
  • Mud. I have tried to make these notes make sense to the dabbler/intermediate user. If something doesn't make sense, let me know and I will try to clarify.


On the whole I have followed the conventions for command syntax that seem to have been around since Dos began (if not before). However, in an effort to simplify the syntax lines, I have taken a couple of shortcuts:

  1. Where there are two switches for the same function (eg. MEM's /D and /Debug switches are synonymous), I have only referred to the shorter version. This is because I reckon it's hard enough trying to remember some of the switches of some of the commands without unnecessarily adding to their number.

  2. I have used the term [path] as in [path]filename to mean whatever is necessary to define the location of filename. The full path - including the drive - can always be used and will always work. Depending on the current drive, current directory, and what (if anything) is included in the PATH environmental variable, it may be possible to abreviate the full path or even omit it altogether.

"Undocumented" Switches

Some of the command switches listed here are "undocumented" or, more accurately, "unofficial" . This means that they are recognised by the command, but MS does not support them and will not attempt to explain how to use them.

In most cases such commands do not provide the safeguards MS likes to see in the commands available to the general user: for example FORMAT c: /autotest will reformat the C: drive without any further ado - no warnings, nothing.

In other cases the function of the switches appears pretty harmless and it would seem that MS is reserving judgment - maybe the switch will be dropped in the next version of Dos (if there is one) and maybe not. For example, it is hard to see COMMAND's /Z switch (displaying the ERRORLEVEL number returned by external DOS commands) causing much grief.

Finally, it is possible that some of these switches are not 100% reliable on all systems - so: user beware!

However, undocumented commands have been around since the beginning of Dos and are an interesting, albeit minor, part of the game.

To avoid confusion, I have formatted undocumented commands to appear in grey (in those browsers supporting the font-color tags).


Many people have, wittingly or not, helped provide the information included in these pages.

First of all there have been the anonymous writers at MicroSoft who wrote the help files of previous versions of Dos. Sometimes the information was applicable and sometimes not, but at least it gave a start.

Secondly there have been the various Dos related newsgroups (not so many posts as there used to be when this site was first put up in early 1997) in which many bugs and workarounds have been discussed.

Finally, there have been the many people who have been kind enough to write directly with relevant information. Wherever possible I have tried to give due credit on the appropriate page. Regrettably, some information has been mislaid over the course of several reinstalls.


The information contained within these pages is (as far as I know) "common knowledge" and so not copyright or copyrightable. However, the presentation is mine and that, as such, is copyright. Having made that claim, anyone who wishes to republish, print, or otherwise disseminate all or some of these pages is free to do so (in whole or in part) for private and/or educational purposes.

If you should have any comments or suggestions,
please contact: Bob Watson
This page last revised:
September 2, 2000.