....sorry....that was a bit vague!....i think you have to sign up to get full screen hd and i think it costs....if not, then you get the postage stamp screen to watch people hurt themselves on.....
Just checked and mine works fine although i do have trouble sometimes when my pc has been running for a long time/lots of things open where by it doesnt open full screen in hd i think. So maybe try a restart?
Or another video?