I lean more towards a temperature and overheating problem.
There are links to some programs in my signature that will help identify temperatures and drive diagnostics.
Everest will give you temperature. Look under computer and then sensor.
Mother board monitor is another 1.
Also, most newer bios's will have a spot to verify temperatures.
You also may want to run hard drive tests after booting off the XP CD, (if you have one).
The XP cd does not have hard drive tests.
If you want to test the drive (I do not suspect this is the problem), you can get the manufacturers diagnostics.
In Everest, expand storage and look at physical to find out what the manufacturer of the drive is.