Unexpected freezings and random restarts?

[cldmafia]

I'm in socal and the recent heatwave has been unbearable and recently I just upgraded my CPU to a 2.9 GHz AMD Athlon 64 X2 Dual Core Processor 5600+.

Now since then my computer randomly restarts itself and freezes out of no where when I'm doing the most menial tasks, such as just having Firefox open.

At first I thought it was overheating due to my house's AC being broken at the moment and the immense heat, but my cpu temperatures read as 40 degrees Celsius most of the time and most of the other temperature readings seem fairly normal, except my Nvidia 8800GT that has an idle temperature in the 70s but I chalk it up to the heat. Besides I find that Nvidia says it's ok to run at that temperature.

In any case, if it wasn't temperature I thought it might be my psu starting to fail, so I gave it good cleaning out since I haven't done so in a while, yet the problem persists.

Does anyone have any ideas or suggestions? Maybe I installed my CPU badly?

 

[DKRON]

Nah if you didn't install your cpu the right way it wouldn't boot. Im guessing you only looked the tempurature of your computer in bios, run the program "Speedfan" while you are logged on and using it to see how hot it gets

 

[cldmafia]

Well I've been using Everest Home Edition to check my temperatures, but I'll try speedfan and see what that says.

Could it be that my psu if dying?

Update:

Everest Home Edition readings (Celsius):
CPU - 40
GPU - 69
GPU Ambient - 55

Speedfan (Celsius):
GPU - 69
CPU - 36
Ambient - 40
Remote - 48
HD0 - 43
Temp1 - 40
Core - 27
Core - 69
Ambient - 55

I don't really understand what temperatures Speedfan is referring to when it lists some of these temperatures, but there they are anyways. Biggest discrepancy between the two seem to be the CPU temperature, yet they all seem to be reasonable temperatures?

 

[DKRON]

All the tempuratures seem fine, speedfan is very accurate. Do you have a warrenty on the psu because i would be replacing it