CDROM DRIVE NOT RECOGNIZED IN DOS:

1. Did you load the proper DOS driver software? Are you sure??? Did you confirm this by examining the config.sys file and autoexec.bat files?

2. Is the cdrom ribbon cable connected and connected properly to the motherboard or to its controller card - with the red line on the cable facing the #1 pin on the card/motherboard?

3. See if you have an irq conflict with another device using the MSD program under the DOS prompt (which may or may not be accurate) or by running some kind of Windows utility like Checkit98