Introduction, Commands and Tips

DOS/Win3.11/95/98 vs. NT/ME/XP/2000(1)
Command Index(1)
Navigating DOS(2)
Tips and Tricks(2)
Network/Harware Utilities(3)
How to make and use bootable floppy disks(3)
Batch Files(4)
Creating Batch Files(4)
Batch file utilities and commands(4)
The AUTOEXEC.BAT file(4)
Types of Batch and System Files(4)
Parameters in batch files(4)
Batch File Library(5)
Subject Index(5)
Helpful DOS Links(5)

Opening DOS(Windows)

If you are using Windows 3.x, there should be an icon in the "Main" folder for MSDOS Prompt. Click on it.

Windows 95/98: Start, Programs, MS-DOS Prompt. OR Start, Run, and type "COMMAND"

Windows NT/XP/2K: Start, Programs, MS-DOS Prompt. OR Start, Run, and type "CMD"

Now, a black window should appear with prompt like this: "C:\WINDOWS>". If you are using NT it will only say "C:\".

It should look like this:

If the DOS window fills up the whole screen, type EXIT, then right-click on the MS-DOS Icon, click "Properties" and select the "Screen" tab, click on "Window" instead of "Full-screen", click on "Ok" and then reopen the DOS window.

Opening DOS in IBM's OS/2

If you are using the OS/2 platform, follow these instructions for opening a DOS session.

1. Open the "OS/2 System" folder.
2. Open the "Command Prompts" folder.
3. Click on the "DOS Window" icon.

Open a command line in NT/2x

Go to Start, Run, type "COMMAND". In previous versions this was done by entering CMD. In some versions of NT entering CMD may invoke previous versions of DOS. In some versions of WIN2x, CMD will open a command line with spaces in the directory name, COMMAND will open the window with the old 8 character limit.

NT/2x Directory System

NT uses user profiles. Each user will have different Desktop and My Documents folders under different names. There is no directory called "Windows", but there is one called "WINNT." Most NT system files will be found in C:\WINNT\System or C:\WINNT\System32. In some cases %SystemRoot% is used to address the system drive regardless of whether it is Windows or WINNT.

The different user set-ups are in the C:\Documents and settings or C:\DOCUME~1. In this directory there will be a different folder for each user who accesses the machine. You may also see Administrator, Default User, All Users and some other funny virtual user folders. Each folder will have its own Desktop, Start Menu, My Documents, Cookies, Favorites and whatever directory structure the user has made beneath. Programs everyone access are usually found in C:\program files or C:\progra~1(same as Windows).

Navigating DOS

For those who have never used a command line envornment, it can be a little confusing and frustraiting. But don't worry. It's still confusing and frustraiting for people who have been doing it for years. Start by using the DIR command.


At the C:\WINDOWS> prompt type DIR for "directory". A list of files should fly up the screen faster than you can read. When the prompt comes up again type DIR/P. This will allow the list to be read one page at a time. Hit enter a few times to get to the end of the list and back to the prompt. DIR is a program that reads scans the current directory and lists all the files. /P is called a switch. The P stands for "page" or "pause"(I can never find out which). When you type DIR/P you are passing /P to the program DIR as a Parameter. You can pass other parameters to DIR. Try typing DIR/W, this puts the file list in "wide" format. Now try this, DIR R*.*. This will display all the files that begin with the letter R. The "*.*" part of the parameter is called a wildcard. A wildcard tells the program that anything after the letter R does not matter. Try this one, DIR *.*EXE. This will display all the files with the .EXE extension.

DIR will display all the files, directories, file sizes, time and date or creation.
DIR|MORE will show you the list and prompt to continue. Similar to DIR/P.
DIR/B for bare or brief, shows only the filenames and their extensions.

8 Character Limits
In early systems there was an 8 character limit on file names and directory names. Directory names and file names also could not contain spaces. This scheme still plays a big role in navigating DOS. The standard Windows folder "Program Files" is called "PROGRA~1." The general rule is to count 6 characters in: "PROGRA" then add the ~ and a number. Since we may have multiple files or directories with similar names, we have numbers at the end of the 8 character name. The number is determined by which file or directory was created first. Since Program Files is a built-in directory it gets a 1. If you create a new directory called "Programs" the DOS name will be "PROGRA~2". To view the DOS names, use this command: DIR/X

In some Windows versions you can open a DOS prompt in specific directory by first navigating to it through Windows Explorer, then going to Start, Run, CMD or COMMAND. In most cases it will open the default PATH directory.

For a full list of DIR possibilities enter DIR/? at the command prompt.

In DIR you placed various slashes and letters after the commands. These are "switches" that modify the behavior of a command. Every command has a different set of switches. A "/A" may mean something for a command and something totally different for another. Sometimes a switch may be preceded by a - instead of a /, sometimes there is no special character at all. For each command look at the help file to see the list of valid switches. You may view the help file of any command by typing the command followed by /? or /HELP in older versions.


Now for a different command. Type in CD.. this should set the prompt to "C:\", meaning that you are now in the root directory C:, C:\WINDOWS is a sub-directory of C:. CD stands for "Change Directory", a program that allows you to move around the directory structure. The .. parameter you passed to program CD tells the program to move up one directory level. Now pass a different parameter, type CD C:\WINDOWS\DESKTOP . This will change your directory level to the Desktop folder. Type DIR/P and look at the file listing briefly. Now minimize the DOS window and look at your Windows Desktop. You should see all the same files. Most of the file extensions will be .LNK meaning that they are shortcuts. CD will allow you navigate through the whole directory structure. You may also look at floppy disks: CD A:(sometimes B: also), or CDROMs: CD D:(sometimes E:).

CD.. puts you in the parent directory(up one level)
CD. refers to the current directory

As stated in the DIR section there is an 8 character limit for directory names for many DOS systems. When using CD to move to a directory with a long name be sure to know the DOS name. Example:
CD progra~1 to go to "program files" if you are in the root of C:\, otherwise use CD C:\progra~1 from any other directory.

Using drive letters as commands
To switch from one drive to another simply type the drive letter. Example: D: or A:. For removable media(floppy, CDROM) you must have the media in the drive to move to it.


PATH sets a directory search order. This is useful in many respects. For example, if you are using a boot disk you are running the DOS operating system from that disk and the more complex commands will only run if you specify the location. If you are at the A: prompt and want to run a command on C: you must type FIND C:\myfile to use the FIND command, or if you are in C: you would need to type A:\FIND C:\myfile. To make things easier, type PATH A:\ at the C:\ prompt. This way the operating system will know to access A: for all the commands.
Some installation programs(especially development environments) will add a line to the AUTOEXEC.BAT like PATH=%PATH%;C:\MSSQL7\BINN this allows programming bins to be accessed from anywhere on the drive.


Type in DOSKEY at the prompt, the DOSKEY program is now loaded. DOSKEY keeps a history of all the commands you type in each session so you can reuse them without typing them in over and over again. You may view your history by hitting the Up-arrow on your keypad. DOSKEY is active in NT by default, but not in Win2K. Consitency is not one of Microsoft's strong points.


DEL is the Delete program in DOS. DEL allows you to delete files. For example, typing DEL TEMP.TMP will delete the file temp.tmp. Warning! Using the DEL command in DOS is not like deleting in Windows, there is no Recycle Bin, the files are gone. If you accidentally delete systems files, you are going to have some problems. Only delete files that you are sure about.


At the command prompt type EDIT. The screen should turn blue with a menu bar at the top. This is the DOS EDIT program and it can come in handy. Click on the "File" menu then click "Exit". You should be back at the prompt. With EDIT you can view and alter just about any file on your system, even ones Windows will not allow you to. Warning! Altering system or program files in EDIT can have serious consequences. Make copies of any file you edit and work on the copy so the original remains intact incase you screw up. Believe me, making copies is much easier that reloading your operating system. This time EDIT TEST.TXT this will open the editor and create a text file called "test.txt". Type in some random text. For a moment stop using your mouse. Press <-Alt-> and then the Down-arrow on your key pad. This will dropdown the "File" menu. This is how navigation was done before the mouse. Learning how to use the keyboard for navigation can be useful something goes wrong with your computer or your mouse wont work. Save your work and exit the editor. In some early versions of DOS it was called "EDLIN." If EDIT doesn't work try EDLIN instead.


REN is short for "rename" and is used to rename files. Warning! Renaming files is as bad as deleting or altering them. Renaming system files can cause errors since the files point to each other. Type in REN TEST.TXT TEST.DOC. This will rename the text file you just created as an MSWord Document. You may now open Word and edit the TEST file like any other Word file. Type REN TEST.DOC MYFILE.DOC. This renames the file as "myfile" but it is still an MSWord document.


TYPE is a program that will show the contents of a file without opening it for editing. Try entering TYPE MYFILE.DOC and you should see the contents of the file you created earlier.


Earlier you learned how to use the /p switch with the DIR command. There is another device which allows you to view directories and file contents a page at a time: MORE. Use the previous command to demonstrate. at the prompt enter TYPE MYFILE.DOC |MORE and hit < enter >. If the file you selected it several pages long, DOS will display the first page and then at the bottom of the screen you will see --more--. DOS is waiting for you to continue. Hit < enter > and it will scroll through the next page.


Type this at the prompt to close the current DOS session.


This is a very usefull tool for searching files for strings(text). If you have lost a file or renamed a file and cannot remember what the name was, you can use FIND to locate it. For example if your name is Joe and the missing file has your name in it, enter FIND "Joe" at the prompt. DOS will search the current directory for any file containing the string "Joe."


Use this to create and name your own DOS/Windows directory.
MD test, creates a directory named "test"


Use this to remove directories.
RD test


Moves files from one location to another, as opposed to copying.
MOVE test.txt A:\, moves the file "test.txt" from the current directory to the A: drive.


Copies files.
COPY C:\myfile.txt A:\myfile.txt


"Extended" COPY. Copies files from one or more subdirectories. Slightly more powerful than COPY. XCOPY has all the same functions as COPY but these switches also available:

/D:m-d-y   Copies files changed on or after the specified date. If no date is given, copies only those files whose source time is newer than the destination time.
/EXCLUDE:file1[+file2][+file3]...  Specifies a list of files containing strings. When any of the strings match any part of the absolute path of the file to be copied, that file will be excluded from being copied. For example, specifying a string like \obj\ or .obj will exclude all files underneath the directory obj or all files with the .obj extension respectively.
/P      Prompts you before creating each destination file.
/S      Copies directories and subdirectories except empty ones.
/E      Copies directories and subdirectories, including empty ones. Same as /S /E. May be used to modify /T.
/W      Prompts you to press a key before copying.
/C      Continues copying even if errors occur.
/I      If destination does not exist and copying more than one file, assumes that destination must be a directory.
/Q      Does not display file names while copying.
/F      Displays full source and destination file names while copying.
/L      Displays files that would be copied.
/H      Copies hidden and system files also.
/R      Overwrites read-only files.
/T      Creates directory structure, but does not copy files. Does not include empty directories or subdirectories. /T /E includes empty directories and subdirectories.
/U      Copies only files that already exist in destination.
/K      Copies attributes. Normal Xcopy will reset read-only attributes.
/O      Copies file ownership and ACL information.
/X      Copies file audit settings (implies /O).


Clears the screen. Clears previous output in the DOS window. Helps close out batch processes.


Shows the environment values and allows them to be changed. See more in Parameters


Formats a disk for use

Genericaly formats a disk for storage use. Most disks are sold pre-formated, nowadays, but the version may not always be compatable with your operating system.

Formats a disk in the B drive.

Places a copy of the operating system on the disk so it is "bootable".

Totally erases disk, regardless of what was on it before.


Recovers a formatted disk.


Use for labeling a disk or changing the present label of a disk. To see what the current label is use VOL



There are many "hidden" files on your system. Some are hidden for a good reason, they are system files that programmers did not want users to delete accidentally. Deleting these files my make your computer inoperable. HOWEVER! Hidden files may also be nasty virii or a corrupted file that is causing problems in your computer. Maybe something you downloaded from the Internet is popping-up all the time and causing your browser or system to crash. You look for the file but it's not there, or it is there but you can't delete it: "Access Denied." Access deined! It's my F!ng computer! Fear not my friend! ATTRIB stands for file attributes. Files my be designated as hidden, archive, system or read-only. There are only four and it's easy ro remember because it might give you RASH. Open a DOS prompt and navigate to the C:\> root directory. Type "DIR" and you will get a list of files and directories. Type "ATTRIB" and you will get a similar list, but it is much longer. Type "DIR IO.SYS" or "DIR MSDOS.SYS" and it will probably result in this:
File not found

Type in "ATTRIB MSDOS.SYS" and you'll see this:

Gee, all of the sudden it's there?
This is interesting. Go to the C:\WINDOWS\ directory and do an ATTRIB on a file called "user.da0". This is hidden file that you should be aware of. Why? Because inside is a tiny databse of everything you do. Every file you open, every application you use, every website you visit. You cannot delete or rename a hidden file. To change the attributes, use the following syntax:
Now you may delete or rename to your heart's content.

To turn attributes on, let us say that you want to conceal files on your PC from the casual snooper, or from the Boss. Use this syntax:
ATTRIB +R +A +S +H filename
- will turn the attributes off, + will turn them on.


A shell interface that makes DOS easier to use. This is not part of most current versions of DOS and would have to be loaded seperately.


These are DOS programs for international language support, they are not available on most PCs sold in the U.S. and must be loaded specially. They are present in version sold in other countries.

KEYB changes the keyboard layout to match foreign keyboard designs. Last time I checked it supported 18 languages. Paramaters of this command alter the configuration of KEYBOARD.SYS.

NLSFUNC is used to load a specific language file, usually COUNTRY.SYS.

Both of these commands have been replaced by GUI programs.

More information


Sets the the NUM LOCK on or off. Cannot be run from the command line, must be in a boot batch file like CONFIG.SYS


Changing the DOS prompt. The default DOS prompt is: diskletter:\directoryname>, example: C:\WINDOWS>. But there are many other options available.

Enter PROMPT $p$g at the command-line for the standard prompt.

Try these others:

PROMPT Sets it to "C>"(which is the old pre-windows prompt)
PROMPT $t Makes the current time(military) your prompt
PROMPT $d Makes the current date your prompt
PROMPT $v Makes the Windows Version your prompt
PROMPT $q Prompt is "="
PROMPT $b Prompt is "|"
PROMPT $e Prompt is "<-"
PROMPT $l Prompt is "<"
PROMPT $_ Prompt is nothing(can be scary)
PROMPT $n Makes the current drive letter your prompt

PROMPT $a Opens up a whole host of options. For example, PROMPT $aHello Jerk makes the prompt: Hello Jerk. You could have a user's name as the prompt: PROMPT $aTeddy Roosevelt. Combinations are also possible: PROMPT $aGeorge $t makes the prompt a user's name an the current time.

If you want a particular prompt to be permanent, insert one of these lines into you AUTOEXEC.BAT file.

Make your DOS prompt look like the Lost hatch terminal:
> :
> : 4 8 15 16 23 42

More recent DOS/Windows versions
$A  =  &
$B  =  |
$C  =  (
$D  =  Current date
$E  =  Left arrow
$F  =  )
$G  =  >
$H  =  Backspace
$L  =  <
$N  =  Current drive
$P  =  Current drive and path
$Q  =  =
$S  =  space $T  =  Current time
$V  =  Windows 2000 version number
$_  =  Carriage return and linefeed
$$  =  $

More: 1, 2


Creates a graphic map of directories and sub directories. For example, use a folder like C:\WINDOWS\TEMP or C:\WINNT\TEMP so you wont be overwhelmed while testing it. Typing TREE in this directory might produce:
MS is a subdirectory of TEMP, SMS is a subdirectory of MS, LOGS is a subdirectory or SMS.

TREE/F will show file names in addition to directories.

To send the output to text file: TREE/A>mymap.txt. The /A will use simple formatting that will read better in the output file.


Tips, Tricks and Other DOS topics

< Ctrl > C

To end a process that is running in DOS, hit the control key, "< Ctrl >", and the "C" key at the same time. This will end the process without closing the session.

The DOS window has taken over my screen!

If you are using any version of Windows, type < Alt > and < Tab > at the same time. This will toggle the DOS window into the Windows task bar. From there, right-click on the DOS box in the taskbar and click on "Properties" then the "Screen" tab. You should change the screen selection from "Full-screen" to "Window."

DOS Devices and I/O Redirection

What is redirection? Typically output from DOS commands is displayed to the screen unless otherwise specified. It is possible to send output to a file, a printer and other devices. Devices are the ports on your PC where data move in and out of memory. Your monitor port is a device, the keyboard and mouse are devices. Serial and parallel ports where printers and other external components plug in are devices. Forcing files to the printer:

TYPE filename>LPT1
LPT1 is the device name for the printer port. It also may be PRN, LPT2, or LPT3
(This may only work if your printer is directly attatched to you LPT port, it may not work on a network)
The ">" refers to the direction of the standard output.
TYPE mydoc.txt>LPT1 will send the document right to the printer.

The above is generally for local printers(meaning connected to the ports on the back of your machine). If you are printing on a network, try using the location of the printer with these commands. Example:

TYPE filename>\\severname\printername
So if my printer server was called "NETPRINT" and the printer was called "HPLASER1", the line would be:

Forcing files to a file:

TYPE filename1>filename2
This will dynamicaly move the contents of one file new file, creating and naming the new file at the same time.
TYPE mydoc.txt>mydoc.doc will create a new document called "mydoc.doc" with the contents of "mydoc.txt"

You may also use >> . The difference is that > will overwrite >> will append.

< Redirect input, used with SORT.

More on SORT.


CRTL+P Copies all subsequent input chars to printer
CRTL+S Suspend further output to a device
CRTL+Z Marks end of a file or stream

DOS Devices
AUX - Auxiliary device, usually first serial port
CLOCK$ - Real-time system clock
COM1 - COM4 - Serial ports(asynchronous)
CON - Keyboard and monitor
NUL - The "bit-bucket", discards output and provides no input.
PRN - First parallel port, often a printer

The typical difference between COM and LTP is that COM devices may go in two directions(I/O) while LPT is usually only for output.

Why use NUL? Forcing output to NUL ensures it is discarded. Programs usually have some kind of output, generally displayed on the screen. program.exe > output.txt will force the output to a file. program.exe > NUL will force the output to "nowhere."

Print a directory listing with LTP1
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