Hi,
If the thermal paste is old, it may not be adequately cooling the CPU.
Or if the CPU heatsink fan is blocked with dust etc. An overheating CPU
can cause all sorts of issues and can cause instabilities in the hardware
of the system. This can lead to rebooting issues as well.
So I would definitely do No.3.
1. Find a suitable surface in a non carpeted room.
2. Switch off the computer and unplug from mains.
3. Make sure you earth yourself by touching the case or use Anti-static wristband as
static can fry the CPU.
4. Remove the CPU heatsink and fan assembly (clean the fan for good air flow)
5. Remove the CPU and remove old paste.
6. Apply new thermal paste (not too much or it can act as an insulator)
7. Re-assemble CPU and Heatsink & fan
8. Retest temperatures.
There are lots of videos on Youtube etc that show you how to carry out this procedure.
Here is a guide that may help. :ar:
http://en.kioskea.net/faq/2947-cpu-is-overheating
Cheers
Dave