If everest is correct, that is a pretty high cpu temp... maybe remove the cpu hsf & reapply the thermal paste, or remove the thermal pad & put paste on there instead.
Some other ideas you can try:
-check the PSU specs since you have some high cpu / gpu power requirements (post your PSU brand / specs please)
-check the memory timings and / or vdimm voltage in BIOS to see if they jive with the memory specs (sometimes you have to set it manually, post your mem brand / specs please)
-if all above is good get
the ultimate boot cd and run memtest / prime for several hours each and maybe run the manufacturer hdd test if possible (will help isolate hw problems with OS problems). If a single stick is bad, so you can just remove the offender and continue dual-channel-less until it can be replaced.
-run a standalone linux cd like knoppix to test the hw,
here is an old post I wrote up to help out getting started with this procedure.