Movie Maker clip previews work. but storyline shows no video (audio still works)

I have very recently downloaded Windows Movie Maker.  I uploaded my video clips to it, and I was able to preview them with perfect audio and video.  But when I inserted them into the storyboard and timeline and tried to preview it, I was only able to hear the audio (the video wouldn't show).  Why can't I see these when they are pieced together?  I appreciate any help.