MSCDEX--Notes

The CD-ROM device driver must be loaded

Your CONFIG.SYS file must include a DEVICE or DEVICEHIGH command that loads
the CD-ROM device driver that came with your CD-ROM drive. The CD-ROM
driver's command line should include a /D:drivername parameter. This
parameter assigns a driver name (also called a driver signature) to the
CD-ROM device driver.

The MSCDEX command must include a /D:drivername parameter that matches the
/D:drivername parameter on the CD-ROM device driver's command line. MSCDEX
uses the /D:drivername parameter to identify the correct CD-ROM device
driver. The driver name is usually a name similar to MSCD000. Each CD-ROM
device driver currently in use must have a unique driver name.

Limit on number of logical drives

The number of logical drive letters available on your computer can limit the
number of CD-ROM drives you can have. The number of logical drives is
determined by the LASTDRIVE command in your CONFIG.SYS file. By the time
MSCDEX loads, some of the available drive letters might be used by other
programs, such as a network, DriveSpace, or DoubleSpace.

SMARTDrive and MSCDEX

If you use SMARTDrive, make sure the MSCDEX command appears before the
SMARTDRV command in your AUTOEXEC.BAT file. SMARTDrive can significantly
speed up your CD-ROM drive by read-caching it. By default, when SMARTDrive
loads, it checks for the presence of MSCDEX; if MSCDEX is present, CD-ROM
caching is enabled. For more information, see the <SMARTDRV> command.