If the drive was clicking (not the ordinary seeking noise, I am talking about a loud unusual click) or made a "clank" type sound then the computer died, the heads are probably gone. This is usually the way they go. Anyway, if that is the case you can fix it by buying an identical drive and replacing the heads. Once it's repaired you'll need to transfer it instantly to a new disk. Look on YouTube for examples of the procedure.
Z