Do you have a raid system in you computer . This would mean two hard drives . if your computer is running in raid on IDE it would give this error if one of the hard drives was not working. you can start buy removing or disconnecting one hard drive at a time and seeing it will boot on one or the other alone. The clicking your hearing is probably the hard drive. Have you tried starting it more than once? Sometimes an old hard drive will get stuck and require a few tries to actually start, hope this helps