If you install the GSpot program(http://www.headbands.com/gspot/), then load the AVI video, it will be able to tell you the codec details required for playback in media player (and hence, Windows Movie Maker).

This Microsoft article was previously published under Q308464

Supported formats for importing content Video files: .asf, .avi, .wmv

Supported formats for importing content:

• Video files: .asf, .avi, .wmv
• Movie files: MPEG1, .mpeg, .mpg, .m1v, .mp2
• Audio files: .wav, .snd, .au, .aif, .aifc, .aiff
• Windows Media files: .asf, .wm, .wma, .wmv
• Still images: .bmp, .jpg, .jpeg, .jpe, .jfif, .gif
• MP3 format audio: .mp3 Read more »

Use the SUPER program to format a video file for use in Windows Movie Maker, using the settings in the attached file. These settings will convert the file to .avi format.

Output container: AVI
Output video codec: MS-mpeg4-v2
Output audio codec: AC3