You cannot convert a Windows Movie Maker file into any other format. The only way to change the format is to Publish/Finish the project, which exports (mixes-down) audio/video properties into Standard viewing format. Once that is done, you can convert the file into whatever format you wish.
Use Windows Movie Maker
You need to convert Quicktime videos to a format compatible with Windows Movie Maker.
convert it into .DAT format
You have to convert it to a file name extension (format) that Windows Movie Maker uses.
You can't play unsupported file extensions in Windows Movie Maker. You have to convert the file to a format compatible with the program.
You can use iTunes to put movies from Windows Movie Maker onto your iPod. I believe Movie Maker files are compatible with Movie Maker, but if you find they are not for some reason, convert them to QT or .mp4 format beforehand.
A Windows Movie Maker project file is in .MSWMMformat.
You can't choose the format type in Windows Movie Maker. Just publish or finish the video first. Then convert the .wmv file to whatever format you like with a video converter.
Windows Movie Maker will not accept .mkv or .flv files. You have to convert the files to a format compatible with the program before you can import them. Windows Movie Maker is limited in the amount for formats it can import/use.
In the Windows Movie Maker program, exporting is accomplished through the Publish or Finish Movie options (depending on which version you are using). In order to convert a Windows Movie Maker project to Standard Viewing format, you have to Publish or Finish the movie.
You do not have any other audio publishing options other than .wma if you are editing it in Windows Movie Maker. My suggestion is... edit the audio in Windows Movie Maker; publish/finish it in .wma format; then convert it to .mp3 using an Audio Conversion program.
First you need to Publish/Finish the Audio project in Windows Movie Maker. The finished product when exported from the program is .wma. Then you will have to convert the .wma audio into .mp3 format using an audio converter.