My computer stopped detecting my DVD-ROM and CD-RW drives, which share a cable. This problem began when I installed a second hard drive (which shares a different cable with my boot drive). Device Manager shows conflicts with my Primary IDE Channel and Secondary IDE Channel under IDE ATA/ATAPI Connectors, but I don't know how to resolve these conflicts, or see if I somehow disabled the port on the motherboard to which the undetected drives are attached. Western Digital tells me the problem is NOT the changes made to my BIOS during installation. The cable and power connections to the drives look fine. Suggestions?

get into the Bios and try to autodetect all the IDE devices.swap the IDE cables and check if its the problem with the cable.replug the cables in the IDE slots properly.check for power and data connections.

1. Make sure both IDE controllers are enabled in BIOS -- they probably are, since they appear in Device Manager 2. While you're at it, try sharansankaran's suggestion 3. Load BIOS defaults If all drives are detected normally in BIOS - 4. Safe Mode - remove both IDE channels and restart the computer 5. Reinstall your motherboard's busmastering drivers, if applicable

Well, this is embarrassing. The problem was indeed a cable slightly disattached from the motherboard. I had been checking the wrong cable! There's such a gaggle of cables and wires in my case, I wasn't following the cable properly all the way to the port. The resource conflict remains, but doesn't seem to cause any problems. Thanks for your replies!