A problem with WINDOWS MEDIA PLAYER??plzzzz help????

am having a problem with "wmp", for the past 3 weeks everytime I click on a video it just lost the frame, and the sound plays right through,i even installed windows media player10thversion,but of no use..when am trying 2 install 11th version a messege appears abt""windows genuine software,........validate..."",,,so plzz tell how to solve this problem......