Problem Reformatting/Reinstalling WinXP.

Is the CD-ROM jumpered correctly? If your hard drive (first) and CD-ROM are connected to separate IDE connectors on the motherboard, then jumper them both to master or cable-select as they're the only devices on their channels. If you had the CD-ROM jumpered to slave, the BIOS is looking for a master device to correspond with it (of which, naturally, there is none).

Also, try jumpering the CD-ROM drive to Master and disconnecting all your other drives to see if the problem persists. If so, try connecting it to a different IDE port on the motherboard. Try a different cable. If that fails, see if you can find a different CD-ROM to try.

If it's recognized from inside Windows, I'd think that the drive itself is perfectly fine, as are the cable and motherboard. It sounds to me like a configuration problem, most likely jumpers, that is interfering.

Oh, and remove your PCI IDE controller card altogether while you're working on this. You can reinstall it later on, but its best to remove as many "foreign" parts as possible.

Jam it back in, in the dark.