Gateway P-173X display issues turning blue  

I am having an issue with my video display on my computer. Everytime I'm playing a game, my screen will turn grey or blue. I then have to turn off my computer and turn it back on. This started a few months ago, maybe once a week. Just recently its occuring everytime I'm in a gaming program for about 5 minutes. I have tried reformatting my computer and using Windows Vista 64 bit ultima edition provided by gateway, I have downloaded the drivers on their support site, and it did not work. I have tried updating my video drivers from nvidia.com to the current drivers, however my comp turn blue or grey at the log in screen for windows. I then have to manually turn it off.

I have tried using Windows 7. I had windows 7 update my drivers. I used the video driver from the gateway support site, and still the computer crashes right when i join a game. Once again I tried updating the video card using nvidia.com current driver, but once again, turns blue or grey at the log in screen when turning on the computer.

I have contacted gateway by the chat function and all the person said it was a driver confict but couldn't do anything more since he was a hardware tech. They have a program where they were suppose to call me back, but they haven't yet. The driver I'm using from the gateway site is nvidia driver version 167.46. No other driver will work. So I have no clue what to do or what drivers update to remove this conflict.

This may sound Stupid but is your monitor fully plugged into the vga port and screwed in?