Windows Live Movie Maker keeps crashing after importing MP4 files

[arcaderat100]

So I just installed Windows Live Movie Maker, and I want to stitch together some of the movie clips I just shot today. The movie clip files are in MP4 format (.mp4 files). So when I import them, Windows Live Movie Maker will just crash, and a box that saids "Windows Live Movie Maker has stopped working". I want to make videos that will retain the HD quality when uploading to youtube. Any solutions?

Please don't tell me to convert files to AVI, 'cause I really don't want to do that. Too time-consuming.

Thanks!!!

Oh, I'm using Windows Vista Ultimate, 32 bit edition.