Converting Mp4 for Windows Movie Maker

Hey gang,
My son is on a PC and needs to convert mp4 video files for windows movie maker--- what is the best way to do this?
Thanks!

http://www.mymusictool​s.com …to-convert-mp4-to-avi.htm

What is the file format that's needed? Handbrake will open most MP4 containers and can export to a number of others. Also, Quicktime can as well, but its export options are more limited without buying the QT Pro version ($30 or so).

You should try out Super, it does many kinds of format conversions, and it's completely free.

Main page: http://www.erightsoft.​com/SUPER.htm
It takes some digging to get the download link, so here it is: http://www.erightsoft.​org/GetFile2.php?SUPER​setup.exe

MPEG Streamclip is free and converts to any format you can imagine. Plus it does batch processing if you need to do a handful of files.