only thing i could get hold of was a plastic aquarium thermometer which i could sit right on the cpu heat sink. The temp reading i got from that was 42C and after two hours of the computer running the temp went up to 43C.

After chatting with a guy on irc tonight about this problem i am having with the computer he advised me to replace the PSU(power supply unit) because to him it sounds like a power drop from that and that is why the computer is rebooting when a load is placed on the cpu. He asked me to run a test which was easy with programs i had and to see what happened. This is the reason he believes it is happening..he also stated that speedfan is the only software he uses to get computer temps because it is the only "Free" software that is true..

I'll replace the PSU and see if that is where the problem lies, if not then i'll replace other things as i get the money  to.

I have opinions of my own -- strong opinions -- but I don't always agree with them.