right click desktop,go to properties, hit the advanced button, then go to the troubleshoot tab. Move the hardware acceleration slider all the way down to none.hit apply then ok
When you do this,now all you have toi do is press print screen on your keyboard at any part of a movie playing,then you can paste it in paint or photoshop or whatever.
When you're done,don't forget to go back and bring the hardware acceleration tab back up