Part 1. Something about Windows Movie Maker
Windows Movie Maker is a totally free program that comes with Windows XP Home Edition, Windows XP Media Center Edition, Windows XP Professional, and Windows Vista. Below are the audio/video formats accepted by Windows Movie Maker:
Video files: .asf, .avi, .wmv
Movie files: MPEG1, .mpeg, .mpg, .mlv, .mp2
Audio files: .wav, .snd, .au, .aif, .aifc, .aiff
Windows media files: .asf, .wm, .wma, .wmv
MP3 format audio: .mp3
Part 2. Remove DRM from iTunes M4P music
The songs you purchased from iTunes store are under DRM protection. You cannot directly import them to your Windows Movie Maker project. However you can burn the protected music files to CD-R or CD-RW disc to make an audio CD and then use some CD ripper software to convert the audio CD track back to MP3, WAV, WMA, etc. And iTunes allows you to burn the protected music files to CD-R or CD-RW disc to make a standard audio CD:
1. Insert a CD-R or CD-RW disc into your CD-ROM drive. You'd better use CD-RW disc as it can be used for more than once.
2. Burn your playlist to make an audio CD. You cannot select the MP3 CD option since it requires the protected music files be converted to unprotected MP3 files.
3. After the audio CD is successfully burned, insert the disc into your CD-ROM drive again. Then you can use iTunes to import the music tracks on the burned disc to MP3 files.
The steps are very simple indeed. Yet, I'd like to introduce a practical application called TuneClone M4P to MP3 Converter(http://www.tuneclone.com ). It applies the virtual CD burning technology so that there is no need to use real disc. You can use it to move your library of M4P DRM protected music to the MP3 format that you can use on any player out there worth its salt. This is a useful tool for anyone looking to break their relationship with the iPod. The best part is that it maintains all of the music file's metadata. You can learn how to remove DRM from iTunes M4P music with TuneClone M4P to MP3 Converter from http://itunesm4ptomp3.wordpress.com/
Part 3. Add the output DRM-free music to Windows Movie Maker
After you get the output DRM-free music by adopting either the disc burning/ripping method or virtual CD burning method discussed in Part 2, now you can begin to import it into your Windows Movie Maker project.
Click on File. Then click on Import. A window will appear. In the window, navigate to the sound or music file you want to add to your movie. Then double click on the file. You'll see the icon for the file in your Windows Movie Maker "collections"