Look at your HD, get the serial #'s & anything else that looks important. Call your manufacturer. Get an RMA # (return merchandise authorization). Most major HD manufacturers (Western Digital, Maxtor, Quantum, etc) have excellent RMA policies. If the HD isn't something they carry anymore, they'll send you the smallest that's available. It's not uncommon to RMA a 10g HD and get a 40g HD in the mail 2 days later. Install the new HD, put the old one the box, send the box back to the manufacturer. I think at most it costs you shipping (could still be pre-paid, but I dunno for sure). I've also known people who remove old, working HD's, get an RMA #, and repeatedly hitting the old HD with a rubber coated mallet (no scratches) before sending it back in.
Indy007
ShiznotZ!