Whenever I launch Windows Movie Maker 2.1 on my Windows XP SP3 system with Internet Explorer 7 or 8, it crashed. The Windows error message indicates the problem is with qedit.dll. Search Engines find lots of reports of the problem, but few solutions. I stumbled on a Microsoft fix for some other Movie Maker problem that seems to have resolved the problems for me. Check out http://support.microsoft.com/kb/969395/, and install that patch.
Good luck, future Googlers. I hope this helps you.