I am trying to edit some MPEG files using Movie Maker, but am having trouble viewing the files. The audio plays, but can't see the video. I think one of the solutions might be to convert all the MPEG files to wmv? But I'm really hoping for a simpler solution because I have a lot of files and I don't really know of a good and trustworthy converter that is also free.

What do I need to do? Any help would be appreciated!