i have a weird problem that started a week ago,
several programs like VLC,MV2PLAYER and MEDIA PLAYER CLASSIC all doesn’t play the video!
they show a black screen and i only have audio(no message or anything).
the only program i found playing video files is windows media player.
i tried kazaa lite mega codec pack (i had an older version of it before the problem began) but nothing works, i still see a black screen in all thoe programs.(all files i tried (wmv,avi,mpg))
what do i need to do to view my videos? 
I had/have the same problem but I found a work-around that works sometimes depending on the start-up.
http://www.moviecodec.com/topics/30834p1.html
My guess it’s some kind of virus or registry setting that is bugged. Really no clue on how to solve it permanently :-(