Computer restarting

[Kakafosha]

it sounds to me like an overheating issue. if possible check ALL your fans to see if they're correctly working. overclocking can also cause some overheating problems, so if you did make any changes i'd suggest you change them back. it might just need a better fan. i dont know much about fans but hopefully someone will reply with some answers. sometimes dust can cause some unwanted heating, but since you said its a fairly new computer that should be the issue. one thing i do, which a lot of other people do as well is take the side panel off your tower to help cool it out even more (not just for a while, i mean pretty much everytime you use your comp)

im pretty sure it isnt a trojan/virus issue, so you wont have to worry about that. i remember the fan on my power supply box died out and i pretty much had the same problem you had. letting it shut down for a while is obviously cooling it down so when you start it up again it'll last for a while. then it ends up heating up again and shutting down.

[Foomanchew24]

If you think it is a heat related issue you can download one of many programs that monitor the temperature and display it on the task bar. I use Motherboar Monitor 5, and have heard that Speed Fan is also a good program, that way you can see what temps your computer is at without having to go into your bios. Try one of those two and see what your temps get up to.