Agree with mosox above. In addition; right-click on the device if it is shown in Device Manager, and choose Uninstall. This will make Windows look for it again on reboot (as long as you don't have Quick Boot - if available in your BIOS - enabled)
Reboot and the drive should appear. If it doesn't, Windows does not have the drivers for that device. You must either run the driver disc that came with the drive or go to the drive manufacturer and download the latest drivers. There are many older CDROMs that Windows lacks the drivers for.