My IDE DVD writer stopped appearing in Windows 7, although it is detected in BIOS. It worked fine until this problem started. It does not appear in device manager or explorer. The drawer opens and closes and the LED goes on, but it won't read or write disks. I have swapped the optical drive for a known working drive, and still no optical drive was detected by Windows. The swapped out unit works fine on another computer. I have installed a new IDE cable, but that didn't solve the problem. The cable is seated fully, no pins are bent, and the plug is properly oriented in the socket. The drive is at the end of the IDE cable and set to "master." There are no other IDE drives on this computer. I looked in regedit to delete the upper and lower limits, but there were no such commands. I have removed and reseated the RAM. Both SATA drives I have installed work fine and there are no other issues with this computer. I would try to repair Windows, but I can't because the optical drive won't read my Windows install CD. What next?