Please help, PC Crashes without BSOD

ttran said:

I think this might me a heat issue, keep track your computer temperature by using cpu-z or gpu-z
I would like to ask you few question, at least can eliminate some potential causes:
-reverse any overclocking on hardware
-disable any auto overclock software
-clean the inside of the box with compressed air
-reseat memory, cables and additiional cards such as graphics cards etc.
-check system temps in bios hardware monitor as I mentioned above

I just bought the PC today. Would I void the warrenty if I open the PC and reinsert the RAM/GPU?