I have been using movie maker for years now. I have a project just started and saved. I wanted to begin another very short project just to email a video. When adding the clip to project Movie maker locked up. That is to say it would not play the clip and even right click would not work. I deleted the project, converted mu little (Panasonic) video to .WMV and tried a new project but with the same results. Once the video was ( I am not sure what you call it but often when adding a clip to the time line Movie Maker makes it better a time box appears at the bottom and you wait for it to do its job) processed but still would not play. I have tried with different videos and none of them work. sometimes the added video looks like it should in the timeline but other times it looks black and white with a wavy line through it. I went back to my other project that I had started and it played (in timeline) fine but the minute I tried to add another clip it locked up also. On a couple of occasions when the added video looked almost like a negative with a wavy line I received a notice that said "This is taking too long do you want to close" (something to that effect) when I did click "yes" and reopened the project I received a message saying "Movie Maker did not close properly last time do you want to reopen" (Again not exact but close) reopening the project did not help. I have Windows 7 and have since I have uninstalled Movie Maker twice once using the control panel and once using CCleaner neither of the re-installed Movie Maker made this situation go away.
I have also posted my problem in a Movie Maker forum with no one sending a reply.

Hope you can help

Rob