i have had my computer nearly 6months now and has worked fine up until recently. It was working fine one day and then it switch itself off. i tried booting it up again and came up with safe mode options. when i selected an option the computer froze and sometimes restarts itself. I have tried starting it in safe and normal but still freezes and i am unable to get onto the BIOS. this has been happening for a while, but the other day it worked fine for about 5 hours and then the same happened. i thought it might have been overheating so i cleaned the heat sink and made sure all the fans are working. Temperature when idle before the problems started was 38C. Tried different power supplies and monitors but nothings helping. Spec: Pentium64 Dual Core 6.8Ghz 2GBRam 200GB HDD using Windows XP Home Edition service pack 1. Any help would be greatly appreiciated. Please use proper thread titles from now on. Thanks.