I'm posting his because I couldn't find any fix on this problem anywhere. The symptom is degraded video performance. Most notably, 4K videos freeze when the mouse is moved. It affects other resolutions as well. Lower resolution videos don't freeze but instead slow down or just have glitches. The affect is stronger when the mouse is moved over the video more than when the mouse is moved on some other part of the screen. Other symptoms are trails when moving a window, transitional graphics very slow, and delayed context menu. This problem can not be fixed by switching video players, clean installing your graphics driver, rebooting win7 or using service packs. These are the technical suggestions given for this problem with the final recommendation being to reinstall win7. I hope my experience can prevent such extreme solutions because the fix could be ridiculously easy.



The fix is to switch to a different desktop style - you might even be able to re-switch back to original style after you switched out of it once. Switch in and out of Aero because it cause a different set of graphic procedures to get loaded and unloaded - you can tell because the screen will momentarily go black before the changes take effect. Switching seems to reboot the win7 graphics system and hence fix the problem. I think the mouse triggers a repaint procedure and if this gets corrupted then it severely impacts the system wide graphics.