Before you get to software to monitor the problem, try to fix the problem.
You're running
windows XP SP3 so your machine is probably fairly old. If you haven't already done so:
1. Open it up, and blow out all of the accumulated dust. Be sure to blow out the dust on, around and behind the fan blades, and clear any dust filter screens.
2. If the power supply appears to have a lot of accumulated dust, open it up and clean it out, as well
Bootable USB.
3. With the case open, turn on the machine, and check to see that all fans are turning freely, and listen for any noise coming from any of them. If any of them appear to be moving slowly or unevenly, consider
cpu temp.
If you're handy, you can dismount a fan that appears to be failing and try to save it by shooting a little WD-40 into the bearing. This either will or won't work, but it's a last ditch attempt to rescue an otherwise failing fan. C
Good luck.