Help! I Cannot See Movies But Hear Sound

Please HELP!
I am downloading Will & Grace Episodes, but when they are finished I can only hear the file and see no video. The sound has a little back feed to it. I am new to this whole Kazaa thing. I don't know much about codecs and stuff like that, but when I play it in Windows Media Player, at the bottom is says, cannot find required codec. When I play it in Quick Player it says cannot find required compressor. What do I need and how do I do it. I warn you I don't know anything about all of this.

Thanx in Advance

Go Here and download the k-lite codec pack v1.7 and then you should have no probs, but you should try installing the BS player and running them in that. :D

Also go Go Here and get GSpot, nice litle program that tells you what codecs you are missing. ;)