PC stopped working

[robaiyat]

when i play games like dota 2 or darksiders 2 ...my PC stopped working and to on my computer again i had to switch off electricity passing button then again switch on the button after a while. my Pc is core 2 duo with 2 gb ddr3 ram and ati radion6450

 

[clutchc]

Sounds like a PSU issue. What is your PSU's make/model? CPU? Gfx card?