Computer Shuts Down Under Stress

[bigmeki]

every time i try to play a heavier game on my computer it closes itself , no blue screen or anything it just closes at first i thought maybe the dust may be at fault but after cleaning it up still same problem , i thought that overheating might had something to do with it but it seem overheating is not the problem either, finnaly i did  a format and updated to windows 8 but the problem seems to be the same, i dont know what to do to get my computer to work again and i need your help
btw its an integrated amd a8800 cpu with an amd hd8570 gpu.

[Allan]

Welcome to the forum

I've moved your thread to an appropriate forum and changed the subject. In the future, when you need help please give your thread a subject that relates to the problem you are having. Thank you.

Please explain what you mean when you say the computer "closes itself". Does it actually power off? And does it only happen when you play one or more specific games?

[bigmeki]

it happens when i play most of my games especially heavier ones like farcry 4 and crysis 3 ,although i didnt use to have any problem with them after 3 moths of no usage of my pc  i came back to encounter this problem , and by what i mean when i say it closes itslef is that it actually shuts down   

[Allan]

If the system powers off on its own it is a hardware problem. My first two guesses are ram or power supply. If you have a spare power supply you can try, I'd suggest you do that. As for ram, here's how to test it:

download memtest (http://memtest.org/). Burn it to a cd using a dedicated .iso burning utility (http://www.petri.co.il/how_to_write_iso_files_to_cd.htm), make sure the cd drive is at the top of the boot order in bios, then boot to the newly created cd and run the utility.