I assume you have a cd drive in your system and it is not being recognized at POST. I would open the system up, disconnect power and data cables, and then reconnect them. If that doesn't work, try another data cable. Is this drive SATA or IDE?
While I would do as Sandman suggested, you may not be comfortable doing that. The problem may be with windows, your bios or your cdrom may be dead.
To narrow it down without cracking the case, you can do this. In each step below the > indicates a click you must make along the path. First click on start and then follow the path.
start>my computer>view system information>hardware tab>Device manager tab>Select dvdCrrom and expand it by clicking the + sign
then delete whatever hardware you find listed there. Reboot the system. If the bois is correct and the hardware is working windows should find it and restore the drivers.
The next step would be to make sure the bios is finding the drive.
