Oh, I didn't realize that.
Does the computer have one or two IDE channels? If you don't already know, you can find out by going into Device Manager in Windows. Check under the entry named "IDE ATA/ATAPI Controllers" and see if it lists both a Primary and a Secondary channel, or only a Primary one. In either case, to which channel is the optical drive attached, and is it listed as "device 0" or "device 1"?