Ooof.
Running a GTX260 on a generic 750W PSU from
ebay is not a great idea.
A game can't
kill your graphics card, so you can be sure its not Empire Total War.
You should download Everest from here:
http://www.majorgeeks.com/download4181.html
And SensorsView from here:
http://
www.stvsoft.com/SensorsViewPro21Setup.exe
Use them to check your PSU voltages and post them back here.
__________________

"Come forth for the cattle call
Confront the evil river you can't control
Wicked ways and venomous eyes
Just human nature in disguise..."- Clouds over California