On my other computer, Sony Vaio Laptop...just recently it's been consantly shutting down everytime I run a big program, or sometimes just shutting off by myself. So I was guessing it was a virus, so I reformatted my computer, since that's the only way I know how to fix it. So in the process of reformatting it, it still was shutting down. So it took like 10 tries reformatting computer till it finally finished. Well, now that my computer has finally been reformatted, everything deleted in C and D drive n' all, my computer still shuts down. Does anyone know the problem? thank you

bad battery or PSU would be my first guess, but I'm sure you have tried running off each to see.

Bad memory mods maybe.

my guess could be the memory or maor likley it would be the heatsink and fans.

Swap bad with good

First thing that pops into my mind would be a bad memory module also. Replace your current ram with new ram and see if it still keeps rebooting. If this doesn't fix it, the problem could be with overheating, or your power supply.