I recently had the same situation on my system, and here's what I did to resolve it. The correct method to use is to specify each drive on a separate line in your config.sys, but combine them into a single line in your autoexec.bat. As for specifying drive letters. you can only specify the starting drive letter - each successive drive will receive the next available letter after the first one. For example: REM config.sys device=c:\sb16\drv\sbcd.sys /d:mscd000 /p:220 /n:4 device=c:\sb16\drv\sbcd.sys /d:mscd001 /p:220 /n:4 device=c:\sb16\drv\sbcd.sys /d:mscd002 /p:220 /n:4 device=c:\sb16\drv\sbcd.sys /d:mscd003 /p:220 /n:4 REM autoexec.bat REM The following must all be on the same line MSCDEX /D:mscd000 /D:mscd001 /D:mscd002 /D:mscd003 /D:mscd004 /L:W You can only run a single instance of MSCDEX, which is why you have to (and are allowed to) combine multiple drive specs on a single line in your autoexec.bat file. The final parameter, "/L:W", assigns the drive letter W to the first of the CD-ROM drives, with the other 3 drives being assigned the letters X, Y, and Z in order. Use whatever drive letters are appropriate for your situation. Be aware that you may or may not need a "Lastdrive=Z" statement in your autoexec.bat. I claim ignorance on the /p:220 parameter listed above for each drive, but if you experience IO Address conflicts it might be a good idea to adjust those addresses to others that are currently unused. Lastly, I assume all of this is to get the CD-ROM drives recognized in a pure DOS session, rather than in a Windows 9x environment. Windows doesn't (or shouldn't?) need any of this to recognize the drives, and drive letters would be assigned in the CD-ROM section of the Device Manager in the System applet of Control Panel. Good luck, and post back if this still isn't what you need to make it work. Jeff Delzer David Spencer wrote: > > When I tried the advice below, the system still booted up and said that all > but mscd000 were not found. The correct number of drive letters were > assigned however, they were all assigned to mscd000. This made the system > extremely unreliable when reading from any of the cdrom drives. After a > while, I'd get a "Not ready reading drive d" error. <snip> ----- PCBUILD mailing list - http://nospin.com Bob Wright:[log in to unmask] - Drew Dunn:[log in to unmask]