[shenuna]

I use Windows system, and there is always mswmm file while using windows movie maker. Now I have found the result.

First, Know the MSWMM File
.MSWMM file is a Windows Movie Maker project file. By saving the project, it allows you to return to the movie and make modifications at a later time. However, if you're satisfied with the movie and would like to upload and share the result through YouTube, you will need to choose "Save Movie File" under the "File" menu (which is different from "Save Project", which creates the .MSWMM file).

Solution I: Save and Play the MSWMM File
You have to open the mswmm file in Windows Movie Maker and save the movie to your computer ( this step you should use Windows computer):
Go Finish Movie > Save to my computer

The 2 options for saving 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.
After the MSWMM file saving as AVI or WMV file in our PC, you can play the WMV/AVI files on your PC and convert them to another video format or burn to DVD.

Solution II: Edit and Burn MSWMM File to DVD on Mac
Talk of burning to DVD, if you are using Mac, how should we do?
First, make sure the MSWMM files had been saved as AVI or WMV format video on your PC, and put the WMV/AVI files to your Mac computer.
Second, directly import the AVI files to your iMovie or iDVD. Most important, if you own the WMV file (iDVD can not support WMV format.), you'd better choose DVD Creator for Mac to edit and burn it to DVD.

All above is the information about MSWMM files, with these tips you can make your own satisfying work!