Video full screen trouble?

When I'm watching a utube video or news video or any video and go to full screen I get sound but screen is black this recently happened I have no idea what happened here any idea's Whwn esc it returns to small video all is good how do I get my full scren back not sure if some one messed with settings please help.

carlo2010-08-09T22:18:18Z

you need to update your video card drivers