pc crashes,cpu or motherboard?

[offvault]

Hi there, I was told that opening a thread in hardware may help me pinpoint what's causing the issue in my PC.
Please take a look at this thread regarding what's going on and what I have managed with ubuysa's help: PC Crashes In Skyrim (it is more than just a skyrim crash )

 

[Corday]

Putting used CPU on MOBO leads me to lean towards CPU as the problem.

 

[offvault]

but the motherboard is a used bought as well

 

[Corday]

Some generic help: How to Test a Computer Motherboard and CPU for Failures