Boot camp/ modern warfare 2 error message

[bluefishswims]

I just installed Boot Camp on my mac and it went smoothly. I also installed Call of Duty: Modern Warfare 2, and it runs fine and i can play just fine, except about every 30-45 minutes of gaming it'd minimize my screen and i see my desktop but no background, so my backgrounds all black and at the task bar i see modern ware, then beside i see an error message, but i see no error message. So i just have to right click, close it all then re-open it all up again and play until it kicks me off again.
And, as far as the 'no background on my desktop' issue goes, i have to right click my desktop and go to properties and act like i'm going to change my background, then my background pops right back up again. it's strange...i don't have a clue what's going on.
I literally installed bootcamp two days ago.
I tried to be as descriptive as possible.
Any advice or help will be nice, thanks a lot

PS- I used Windows Vista Basic to install my boot camp on my iMac.

 

[bluefishswims]

oops i said "modern ware" I meant "modern warfare**"