So first off I do not know much about computer hardware and etc like that but I pretty much know the basic bits inside, Graphics card, RAM, HD and PSU stuff like that. So my computer crashes usually when playing games (but not WoW :S) also watching HD videos on Youtube can trigger it orrr sometimes MSN and almost 100% chance to crash in a League of Legends game, how do describe the crashing... well the sound goes to an annoying constant noise sounds almost like a jackhammer on the street.. mixed with white noise from your tele, sometimes the screen just freezes and sometimes it goes black. sometimes it even restarts itself. It used to have a small chance to do it like.. once a week or 2 weeks which i could live with but ever since i thought i "broke" the computer my friend had a look at it to fix it, he thought that i busted my PSU so he put his in to see if it would work but it didnt.. turns out i just pulled a wire out by mistake XD. so now he's put my PSU in and cleaned away the dust from the inside and it crashes more often then ever.. every game, which is really annoying of course. I'd like to know what might be causing it.. maybe i need a new PSU or maybe its overheating or simply just my computer is getting old and shitty. just to say it does NOT blue screen of death me.. just dies completely!