Saving Audio Only from Windows Movie Maker

“Is it possible to digitally record just the sound track from a movie captured in Windows Movie Maker?”
The Windows Movie Maker team anticipated this type of request and included a feature to export only the audio portion of your video as a WMA file. Instead of placing the movie clip on the Video portion of the timeline, drag it to the Audio/Music section of the timeline. When you go to publish your movie, Windows Movie Maker will ask you about audio quality settings and create a WMA, instead of allowing you to choose a video format.

Are MSWMM Files Mac Compatible?

“How do I convert mswmm files to a Mac compatible file?”
mswmm files are the project format for Windows Movie Maker. The files tell Windows Movie Maker things about your video editing project like what video clips are used, which audio files you imported, which transitions go between which clips, and which effects are used. These files are essentially readable only in Windows Movie Maker and will definitely not work on a Mac. The two options for saving out a video file from Movie Maker are either DV-AVI or WMV. To create a Mac-compatible video file, open the mswmm file in Windows Movie Maker, save the movie at the highest quality setting WMV or preferably as a DV-AVI format file. Import this finished AVI or WMV file into iMovie or other Mac video editing application.