S T ADVT

TUTORIALS
DOS Basic DOS HOME DOS Introduction DOS History All Commands Applications Command line File Extensions Boot Disk Batch Files OS Definitions Internal Commands External Commands RC Commands Top 10 commands Ques and Ans. DOS Quiz DOS Quiz DOS Exam

MS - DOS Command

« Previous

Next Chapter »

Microsoft DOS mscdex command

Quick links

About mscdex
Availability
Syntax
Examples
Errors and issues

About mscdex

Mscdex is a CD-ROM "redirector" that enables CD-ROM access from the MS-DOS.

Availability

The mscdex.exe or mscdexnt.exe command is an external command that is available in the below versions of Microsoft operating systems.

All Versions of MS-DOS
Windows 95
Windows 98
Windows ME
Windows NT
Windows 2000
Windows XP

Syntax

Syntax: MSCDEX.EXE /D:x /M:n /E /V /L:x /S /K

/D:Device name	Allows you to specify the name for the driver. This must be identical to the device name in the Config.sys file. Usually MSCD0001 is commonly used.
/M:<n>	Specifies the number of sector buffers to cache the path table of a CD-ROM disk. Typically, each drive should have four to five buffers. The larger this number is, the less your computer will read directly from the CD-ROM drive.
/E	Tells MSCDEX.exe to use expanded memory.
/V	Displays information on memory usage when you boot your PC.
/L:<drive letter>	Specifies the letter you wan to assign the first CD-ROM drive. Such as D:
/S	Allows the CD-ROM to be shared on MS-NET based systems.
/K (Japanese)	Tells MSCDEX.EXE to use any KANJI file structures, if present rather than the default of alphanumeric file structures.

Extra Notes:

When loading the MSCDEX line in Windows 3.x that you specify the LASTDRIVE= statement, such as LASTDRIVE=Z

Examples

Below is an example of how the MSCDEX line should look in your autoexec.bat:

LH C:\WINDOWS\COMMAND\MSCDEX.EXE /D:MSCD001

Remember that the above example, if used, must have the same device driver name as the CD-ROM driver in the config.sys.

Additional information about the autoexec.bat and config.sys can be found on our autoexec.bat and config.sys page.
Additional information about loading MS-DOS CD-ROM drivers can be found on our CD-ROM drivers page.

Errors and issues

When booting I receive message "MSCDEX is already running" and if I continue, all programs will stop running.

It is likely that you have more than one MSCDEX statement in your autoexec.bat. Edit the autoexec.bat and place a REM in front of one of the MSCDEX lines in the autoexec.bat. Additional information about editing the autoexec.bat can be found on our autoexec.bat and config.sys page.