Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

                            CONFIG.SYS Commands
 
The CONFIG.SYS file is a text file that contains special commands. These
commands configure your computer's hardware components so that MS-DOS and
applications can use them. When MS-DOS starts, it carries out the commands
in the CONFIG.SYS file. Typically, the CONFIG.SYS file is located in the
root directory of drive C.
 
CONFIG.SYS commands
 
The following CONFIG.SYS commands can be used only in the CONFIG.SYS file:
 
<Buffers>                 <Files>
<Country>                 <Install>
<Device>                  <Lastdrive>
<Devicehigh>              <Numlock>
<Dos>                     <Shell>
<Drivparm>                <Stacks>
<Fcbs>                    <Switches>
 
The following commands are commonly used in the CONFIG.SYS file and can also
be typed at the command prompt:
 
<Break>
<Rem>
<Set>
 
The following special CONFIG.SYS commands are used only to define multiple
configurations within the CONFIG.SYS file:
 
<Include>
<Menucolor>
<Menudefault>
<Menuitem>
<Submenu>
 
For more information about defining multiple configurations, see
<Multi-Config Commands>.
 
Special characters in the CONFIG.SYS file
 
The CONFIG.SYS file can also contain the following special characters:
 
   ;   Specifies that the current line is a descriptive comment
       and should not be carried out. Insert this character at the
       beginning of the line. (You can also insert a comment by using
       the REM command.)
 
   ?   Specifies that MS-DOS is to ask for confirmation before
       carrying out the current command. Insert this character
       immediately after the command you want to prompt for, without
       any intervening spaces, but before the equal sign (=). For example,
       to have MS-DOS ask for confirmation before carrying out the
       DOS=HIGH command, you would change the command to read
       DOS?=HIGH. To have MS-DOS ask for confirmation before
       carrying out the DEVICEHIGH /L:1,7280=MYFILE.SYS
       command, you would change the command to read as follows:
       DEVICEHIGH? /L:1,7280=MYFILE.SYS
 
Bypassing CONFIG.SYS and AUTOEXEC.BAT commands
 
If you are having system problems that you suspect are caused by one or more
commands in your CONFIG.SYS or AUTOEXEC.BAT file, you might want to bypass
some or all the commands in these files. (For information about bypassing
DriveSpace, see the next section.)
 
♦  To bypass all the commands in your CONFIG.SYS and AUTOEXEC.BAT files,
   press the F5 key immediately after starting your computer, when you see
   the text "Starting MS-DOS...".
 
♦  To bypass individual CONFIG.SYS and AUTOEXEC.BAT commands, press the F8
   key instead. MS-DOS will then prompt you to carry out or bypass each
   command. To carry out all remaining startup commands, press ESC. To
   bypass all remaining startup commands, press F5.
 
To disable this feature, add the <SWITCHES /N> command to your CONFIG.SYS
file.
 
Starting your computer without loading DRVSPACE.BIN
 
DRVSPACE.BIN is the part of MS-DOS that provides access to DriveSpace
compressed drives. Normally, if your hard drive has been compressed using
DriveSpace, DRVSPACE.BIN is loaded even if you press F5 or F8. There are two
ways to disable this:
 
♦  To start your computer without loading DRVSPACE.BIN, and to bypass all
   the commands in your CONFIG.SYS and AUTOEXEC.BAT files, press CTRL+F5.
 
♦  To start your computer without loading DRVSPACE.BIN, and to bypass
   individual commands in your CONFIG.SYS & AUTOEXEC.BAT files, press
   CTRL+F8. MS-DOS will then prompt you to carry out or bypass each
   CONFIG.SYS and AUTOEXEC.BAT command. To carry out all remaining startup
   commands, press ESC. To bypass all remaining startup commands, press F5.
 
Note:  If you bypass DRVSPACE.BIN, you will not be able to gain access to
       your DriveSpace compressed drives until you restart your computer
       with DRVSPACE.BIN. (Your compressed drives will remain on your hard
       disk as hidden files with names such as DRVSPACE.000. Do not delete
       or rename such files.)
 
To disable this feature, use the <DRVSPACE /SWITCHES> command.
 
For more information about your CONFIG.SYS file, see the chapter
"Configuring Your System" in the MS-DOS User's Guide.
 
                                      ♦