I can't see video in movie maker!

I have a problem with movie maker. I was starting to make a video with scenes from episode from tv show. But episode is abou 40 minutes, so I was thinking this is a problem, because short video can work properly.
I saw here I need to find a codec, so i download and install codec, but now sistem report me a problem,that I don't have appropriate codec and can't see any movie!

HELP ME PLEASE :(
( sorry for my bad english)