Just downloaded a new desktop theme for W8.1 today. I usually disable screen savers but didn't this time. Left the game for a minute and came back to a frozen MW and the got the MW has stopped working. Started back up and watched it and was lucky enough to catch it throwing up a screen saver and saw it lock up. Odd behavior but lesson learned. Works fine on 8.1 except if I play for a few hours and save and exit I get the MW has stopped working thing. I have MGsO and about 8 other mods.

Any Screen Savor that goes full screen would lock up the game. I know it did back in the Win98 days when I used a screen saver for a while.

You might look in the options of the screen savor to see if it can be disabled on Full Screen activities, as most screen savers do not recognize full screen activities as something to not trigger on. At least they used to. I honestly have not used a screen saver in years.

Just figured it out, I think. Windowed mode. Only game I have to do this for. I always disable screen savers but I just downloaded it before starting the game and hadn't got to it yet.