[SadisticSid]

I'm convinced my laptop hard drive is about to die. The PC's been freezing with the hard drive light solidly on, Windows has said the registry's been corrupted on a clean shutdown, and just this morning I heard two worrying high pitched grinding noises followed by another freeze. However, I've run surface scans and all the standard crap which say everything's fine. The SMART monitoring thing I installed says likewise. Now, I want to send the drive back to Acer for a replacement, but I'm concerned they'll not be able to reproduce the freezes (they happen once every couple of days, at most) and just send the pile of junk back. Does anyone know of a program that will thoroughly scan the drive and perhaps pick up errors that Windows and SeaTools won't?

[neoterran]

look in the system event log for "disk" if you see "a paging error was reported on hard drive x" or "disk x has a bad block" or similar, then your drive is getting bad sectors. You can export these to a text file for "proof" In either case, chkdsk /X /R and a reboot may reclaim some of your data and allow you to continue for a while.

In windows Vista, windows will tell you if the hard drive is about to fail, FWIW

[SadisticSid]

I checked the Event log. No anomalies, in fact nothing's ever said I've got an error. It just freezes on IDE activity.

[Descenterace]

The ultimate hard disk tester: a rubber panel-beating mallet.

Step 1: Backup all your data.
Step 2: 'Test' the hard disk with the mallet, which leaves no marks.
Step 3: Get it replaced under warranty.

[futureshock]

Try a Live-CD (Knoppix, Ubuntu whatever) and try to read or write data to your HD over 24 h. (Playing and encoding mp3s or so.) 
If you don`t get noises or errors its Windows and not your HD.