Problem...

[Cass]

So here is my problem mabey some people smart with computers can help me out here.

My comp will run none stop idle in windows forever no problem. but the thing is when i start up any game it frezze's and only thing i am able to do is restart just so it will do it again less than 5 min into the game being re-opened. i thought it might be a tempurature thing so i ran the soltek hardware monitor programe that came with my mother board, it shows in red numbers the cpu being at 150F but I dont know if that is right. I have done nothing to the clock settings and it has the stock heatsink on it. is the CPU over heating? or what else might be wronge here?

my computer is.

AMD Athlon 64 3000+ 1.8GHZ
Soltek k8tpro s939
Radeon 9800pro
random Power suply that came with the case
Sound blaster audigy LS