I'd like to know a work around for this too, as Movie Maker crashes for me too... but usually with movies reaching the 10 minute mark, consisting of half a dozen or so clips & what not...
plenty of RAM, drive space, CPU power etc... my last one I made last week, was 7 minutes long & couldn't add anymore images at end after credits even one more transition or video effect would crash it, luckily I started getting in habit of saving the projects every few clips, so incase it crashes I have something still there next time I load it.
I could use my copy of Adobe Premiere I have, but I like Movie Maker for quick little projects...
and Nero 6's one app for making movies, works, but I've had troubles with outputing the videos in past sometimes...