On the hardware side...
I'd expect a desktop hard drive to last quite a bit longer than three years. In my experience they tend to fail as soon as you get them or many years later.
If you've got your system up and running can you not just scan the disk for bad sectors?
In XP select My Computer, right-click the drive you want to scan then Properties > Tools > Check Now.
Opt for a thorough scan that scans for bad sectors.
If you've got bad sectors then you've got a hardware problem - in theory you can continue to use a drive with bad sectors but it's not wise. They tend to spread fairly rapidly.
In my experience if a hard drive doesn't suddenly fail completely - it usually only takes a few days from the onset of the first symptoms to complete failure. Frequently as the problem gets worse and bad sectors spread you hear more and more odd noises coming from the drive as it tries again and again to retrieve data from corrupt parts of the disk.