Overheating Or Ram Issue

I have a Toshiba laptop with windows XP and I have a problem with it randomly turning off. I don't know if it's a overheating issue or if I'm using to much ram or what, I dunno.

Here's the problem: My computer randomly shuts off while I'm using it. Sometimes it'll shut off when I have a lot of programs running, sometimes it'll shut off when I have just a few running. It's been a problem for a while now, and recently I just downloaded WoW, and every time I try to play it, It'll let me play any where from 10-30 mins, but the comp always shuts off on me no matter what. I downloaded a couple programs to try and diagnose the problem, but I'm not getting anywhere. I Dl'ed PC Wizard to see my temperatures and it will only show my CPU temp which is at an average of 40c (MIN=29C MAX=51C). I also Dl'ed speedfan and it also only shows my CPU temp, and says the overall fitness for the drive is 98% and the overall performance for the drive is 100%. I can't seem to find anything about the fan settings or temp, and I'm not that tech savvy, so I don't know what to do. I need some help. Does anyone know what the problem can be? Any help/advice would be appreciated.


Oh, and when I first start up my comp around 50% or more of my ram is being used, I tried using programs to free up unused ram, but my comp still shuts off while playing games or having a lot of apps running. I need to figure whether its my ram causing my comp to shut off or if its overheating.