Wow....
On the surface it sounds like processor overheating, I know you've said you have checked but look at the actual processor, make sure the heatsync is sitting properly. You want to make sure the plastic clips are in place on either side of the heatsync holding it on. I've seen some people have it turned wrong too where the bottom of the heatsync has a lip and that lip was sitting on the processor instead of off to the side like it was designed to be. You want the heatsync to lay flat on the processor. And for it to be CLEAN.
BTW 60c scares me, getting that close could actually be your problem, clean out your fan and heatsync with canned air (don't spin up the fan though as it is built to only spin so fast and it will do funky stuff if it gets going faster then that (In other words don't go get an air compressor and leave a steady stream of air on it, or atleast turn on the regulator down quite a bit)
I'm really doubting it's memory unless you increased your usage on sunday from saturday. I could be wrong on this, it's just unlikely.
It's not the cpu fan stopping or sizing up. I used a fan throttling utility by nVidia to test it and it was fine (4400 rpm).
The case has two 120mm fans with variable speed controls (front and back), a fan on the cpu. I cleared the fans of any dust and debris, and they were a little dirty, but spin freely.
Reading that it SOUNDS like you only cleaned the case fans and didn't open up the case, if I assumed a bit much still be wise to clean it up and check the heatsync.
It's not the hard drive. I used chkdsk, fdsk to correct 2 errors, then I reformatted the SATA drive, reinstalled windows xp. twice. I installed a HD monitoring utility, the temps are great.
Chkdsk finding errors isn't a Hard Drive problem 99% of the time, it's a "I shut down windows incorrectly" problem and this part of the pagefile didn't get removed or this file was written funny or didn't match the file allocation table. What the other gentlemen was thinking was what S.M.A.R.T. calls "Reallocated Sectors" typically when those start getting used, it's time to backup your hard drive and get a new one because you are going to see more of them, not a matter of IF, a matter of WHEN.
What you had, could have been fixed with "chkdsk C: /f" and rebooting let it run upon bootup and that would have been fine, 2 isn't all that bad either, I've seen some that literally took an hour and a half to run chkdsk because it was fixing so much crap.
Another potential problem is bad capacitors. Basically they look like little battaries with either X K or a peace sign on top of them. Typically the one's I see go bad are the one's with X's or peace signs (X's more then anything). I'd be really surprised if that was the case though, you can tell if that's the problem if the top is starting to pop out some. That would change the voltage to whatever part is down line from it and would grow worse as time went on. (
www.badcaps.net)
I highly doubt it's your video card and I've never seen a power supply cause those kinds of symptoms before, typically it's either working or it is not. Even had a person bring in a computer that the capacitor had blown out on the power supply and the computer still worked (though smelled like really nasty ammonia)
Dismissing overheating because the system is set to cut off for safety purposes at 75c and you are only reaching 52c isn't wise. Open up your case and look at it.
Told me their computer wasn't overheating too... (and it spun too!)
Love,
Charles~
www.CharlesTheTech.net