Ok I've just moved back to uni and my desktop computer has started freezing up completely and requiring a switch off when running fairly intensive games for a little while (stuff like l4d2 on high and Prototype).
I think it might be overheating because when it freezes if I switch it off it won't start up again until I leave it for a short while and if I don't run any games it doesn't appear to freeze at all. I wasn't sure if this problem was related to an issue I had a while ago before the christmas break where the computer was acting in the same way but far more commonly.
I discovered at that point that the inside of the computer was VERY dusty so I bought some compressed air, cleaning stuff and thermal paste (my flatmate knows a bit mroe about computers so he walked me throug hall of this). I aired out the inside of the computer including the heat sink of the CPU (the dust was stopping the fan running). I cleaned off the thermal paste and reapplied the new lot as directed very carefuly, replaced everything and it ran fine. I've taken my computer home over the christmas break and it's been over a month since I cleaned it out and the computer has run perfectly fine it was only the day I ran it once returning to uni that I had this freezing issue.
Looking inside the case shows all the fans working perfectly fine (the top one occaisionaly had issues starting up over christmas but always did in the end and runs fine now) so I'm really at my wits end at what wrong unless I've knocked something loose that I can't find.
basic deatils of my comp are:
Intel core 2 duo e6600
Any help would be appreciated and if you need any more diagnostics I could get from somewhere that'd be fine. Thanks for any help you can give