Did you add another drive recently?
If not then check if the IDE connector is loose and attach it securely. Also check for bends on the IDE ribbon cable.
If you have added another drive, check if the master/slave jumper settings for your drive and cd/dvd are correct.
If not then check if the IDE connector is loose and attach it securely. Also check for bends on the IDE ribbon cable.
If you have added another drive, check if the master/slave jumper settings for your drive and cd/dvd are correct.