I have leaved the game open on easy lvl and the game crashed after 1 min. Destktop and back in game after 5 sec

I have installed the software, one was on my cpu other not.

I have played 1 game 23 min whithout crash and then crushed on desktop again.

Nvidia was trying to change resolution i think.

Any other advice?

My gtx470 after 2 min. game crash on desktop. Sometime back in the game after 5/6 second and sometime not and give to me the crash report... I have opened the cpu, cleaned inside the coler, all is fine. I have reinstalled windows7 I have tested the temprature of cpu and other stuff and all is lower ...