I have an HP Pavillion a6224n with Nvidia 9800GT graphics.
Everytime i start a game on my pc the screen says moniter going to sleep,and shuts off my screen.
I cant get the screen to do anything after that,so i have to shut down and restart.
It seems like the problem is getting worse.
If you are using windows 7,go to this address:
Control Panel\System and Security\Power Options
And on the left side,choose "Change when the computer sleeps" and then make sure "Put the computer to sleep" option is set to Never.