Computer Shutting off Randomly and Doesn't report Temps Properly

[Jiinxycat]

I am extremely confused. My computer at first it was perfectly fine than when I am playing mincraft that is when it all began. My computer just shut off. I thought okay maybe it was using too much memory I only have 1792MB RAM less before cause I was running windows 7, minecraft tended to use up memory for no reason so I played it on my older computer with more memory. If it ended there I would have known the issue but nope I was playing eve a little later maybe two weeks later and my computer shuts off. I thought maybe it was overheating but the temps are okay except for every program either not reporting the temps or speed fan telling me the Temp3:-128°C CPU:0°C. I changed my operating system to XP too so the memory wasn't taken up as much as it was updated my Bios and everything but it continued to shut off randomly when I play a game and now when just idleing. It was okay when I put it in the freezing cold window but it is really cold in the room all the time anyway where I am, so I don't know how it can be overheating and if so why randomly overheat when I am not doing anything now. It never did this before either it just randomly started happening on top of that the computer is only 6 months old. If anyone has a solution on what is wrong with it and what I can do please HELP ME!

Here is my computers information:
Operating System:Microsoft Windows XP Professional(5.1, Build 2600)
System Manufacturerfor some reason doesn't show up and just repeats) System Manufacturer
System Modeldoes the same thing) System Product Name
BIOS: BIOS Date:5/17/11 20:15:24 Ver:11.01
Processor: AMD Phenom(tm) II X4B55 Processor, MMX, 3DNow(4CPUs), ~3.2GHz
Memory:1792MB RAM
DirectX Version: DirectX 9.0c (4.09.0000.0904)

I have been looking up the problem and some people have similar issues, but only sort of. It seems to be a problem with AMD processors. I unlocked my computer to 4 cores and if it is messing up due to this than I will cry. I need the processing power why is it messing my computer up so bad it was built to be able to go to 4 cores there is even an option for 6 but I think this model can't go that far even though it's an option in the BIOS.

 

[scottiemedic]

What temps do the BIOS report? The Windows program may not support your CPU for probing.

 

[davcon]

After a few years thermal paste can dry up and become ineffective.
Re-applying new thermal paste might be an option.