Movie Maker was working Okay until I installed Windows updates. Now the preview is black. Someone said to check the video file types, but the preview for pictures is black also so I don't think it is about the video file type.

I have MM 2012, Windows 7 64bit. I ran FixIt and it didn't find a problem. I don't really understand Codecs so I don't know how to check that. Please let me know what I should try. Thanks.