Pc shuts off when running WoW all of a sudden.

Hey all new here... Been trying to troubleshoot this problem for a long time now and cant seem to fix it permanently. I cleaned out pc case and dusted everything. Pc seems to just shut off when playing WoW or gw2 or any other game other than LoL. After it shuts off, I have to wait like a good 10 seconds to even a minute before I can even power it back on.

PC specs:

Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120830-0333)
Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: GA-970A-D3
BIOS: Award Modular BIOS v6.00PG
Processor: AMD FX(tm)-4100 Quad-Core Processor (4 CPUs), ~3.6GHz
Memory: 6144MB RAM
Available OS Memory: 4094MB RAM
Page File: 1658MB used, 6525MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 32bit Unicode

FAN: Asetek 510LC Liquid Cooling System 120MM Radiator & Fan (Enhanced Cooling Performance + Extreme Silent at 20dBA) (Single Standard 120MM Fan)

VIDEO: AMD Radeon HD 6870 1GB GDDR5 16X PCIe Video Card

POWERSUPPLY: 700 Watts - XtremeGear SLI/CrossFireX Ready Power Supply

Any ideas? I run speedfan and it all seems to be under 60c I also have a eternal HD for 2 tb but I dont have it on or connected when this happens.

 

Ok I got a new GPU and its been running fine for a week. All of a sudden last night it shut itself off again. No warning signs or anything just like if someone unplugged it. Since I got new GPU all temps are well under 45c if that even. How ever it still just randomly shuts itself off when playing games. I get a message sometimes it says windows does not have enough resources and to switch themes or stay same.

I bought a AMD radeon HD 7700 series

Could it be my power supply? Thats my last thought I have. I completely took out all my fans and blew them with compressed air... not 1 speck of dust in my entire PC.

In event viewer I got error 41 The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

 

That almost sounds like a cut off. Like when something overheats and shuts down, but not like a motherboard or GPU shutdown, more like the PSU type of setup. Welders have it, as do certain high grade stereo sets.
Not always heat either, maybe a power surge?

If you are plugged into a power bar then try either a different one or none at all (although not recommended) .

If that makes no difference then is there any way you could try a different PSU?

Just an idea, but my experience with electronics over the years has sown me this kind of "Cool Down" period after a trip switch has popped.
Never heard of having to wait to power up from a software shut down.
To clarify, I class any sort of computer component such as motherboard, cpu, gpu, ram etc too all be controlled by software. The PSU is not but most have a sensor and safety shut offs.
It also occurred to me that usually if a GPU overheats or starts dying, it's a series of shut downs, like the creen goes black but you can still hear sound, or maybe a reboot.
What you are describing sounds more like a power down and from what you say... an instant one, which again why I would be thinking electrical, not software.

But I have been known to over think things :-D