If you havent adjusted any physical settings on the harddrive, I'd say this is drive failure.
If it wasnt making such a high pitched wine I'd go with a corrupted windows installation, but because of it im going to say drive failure. If you have an extra lying around, Id switch out harddrives before you take the risk of possibly frying another part in your computer after it dies. If you can boot up, download whatever your harddrive manufacturers harddrive diagnostic tool, and see if its really dead.
Go through this list and download the tool for your harddrive, http://www.tacktech.com/display.cfm?ttid=287
Once installed do a diagnostic and see if there are any problems.