Cd/DVD Rom Not being recognized

Both my dvd-rom and cd-rom are not showing up under my computer both they both show under the bios. I have tried uninstalling and scanning for new updates it does no good. I get an error message 39 from windows stating Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. This has happened once before and something had to be done in the registry. Any ideas?