Firstly i suspect this is a Power Supply problem, thus i am posting it here, if it is not correct feel free to move it.
Here is my problem:
My PC startup fine, runs my Windows 7 ultimate, everything perfect.
As soon as I try to play a game like for instance COD4, WoW, Guild wars, etc. it launches and then after a min or two of game-play my PC just totally loses power, no errors, no nothing, just a dead computer. If I don't play anything and just browse or watch a movie its fine, but it seems to me that anything I run that uses my PC's Graphics card causes it to die. I can leave my PC running through the night without any problems, but as soon as n run something it loses power.
Also I recently installed new Nvidia drivers, but I am not sure if it is possible for software to cause a total PC shutdown.
Also i have checked my power source and everything else stays powered, including my screen (Although it is plugged into the wall not my Power Supply) and Ive thus excluded the possibility of power failure.
My theory is that perhaps my Power Supply is broken and as soon as the GPU kicks in it draws to much power and then cuts of my whole systems power? Is this possible? Mite anyone else have a different explanation or share the same problem?
Any advice or help would be much appreciated. Thank you in advance.
Check your GPU temps. If they seem fine your diagnosis could well be correct. If you have available Onboard gfx, disable your GFX card and try running a game. If it works (obviously badly) then we can narrow it down to GFX card or PSU. If the GFX card is running nice and cool, drivers are fine etc, then we can then narrow it further to the PSU. Whats the specs of your machine?
Also if you havnt done it before, look at a guide showing how to remove the old thermal paste and apply new. Some people get this wrong (you dont need to use the whole tube of AS5) You also might want to clean dust from the heatsink/fan and make sure the fan is actually spinning.
CPU overheat ought to trigger the mobo's alarm (same piezo that beeps when your machine posts) before a shutdown.
You said you have a "550W" PSU, but not the brand or model. If it's a Diablotek or other Chokemax, it could still be part of the problem.
Thank you very much everyone for your replies.
The paste seemed to have done the trick, my PC now runs at a cool 33°C in idle, and goes up to about 40°C while I'm gaming. ^^
Also thank you for reminding me that i had to properly remove the old paste, got some alcohol and it worked like a charm.
As for what brand my PSU is, I am from South Africa, and yes I realize it is mostly a UK site but I find it useful so I use it.
And I think the PSU is some imported "thing" the name not being worth the mention, its still running perfect now tho.
Once again thank you to everyone for there input, and have a great day.