Just installed NV and did a quick test (well, as quick as the dialog will allow) to see if it works on my system. I'm pleased to report it works just fine. UNTIL I exit the game.

It appears NV quits but a fullscreen mostly black "window?" is left. Actually two "windows" are visible - a small one in the upper left corner overlays a fullscreen "window" (window is in quotes because although there are what appear to be window frames, there is no control). I can Ctrl+Alt+Del to get to the Task Manager, but the Task Manager appears behind the fullscreen black "window" so I can't force close the remaining artifacts from the game. This means I have to reboot the machine before I can continue with anything else.

Anyone else see this behavior?