Question: Windows Media player & DIVX

Well you did put WMM in your post

As to the issue, I don't much, but this was on Microsux website:

Although you can play a file in Microsoft Windows Media Player, you may not be able to import the file into Windows Movie Maker even though this article lists that kind of file. You may not be able to import the file if the codec that was used to encode the audio or video is not a codec that is included with Windows XP. In that case, you may be able to re-encode the video or audio by using Windows Media Encoder, and then import the video or audio.

Note The MPEG2 format has several codecs that are not supported by Windows Movie Maker. Even if you have downloaded and installed these codecs on your computer, files in the MPEG2 format may not work in Windows Movie Maker or may cause other problems. Converting the MPEG2 format to another compatible format may work for most MPEG2 files. However, some MPEG2 codecs include copy protection schemes that will prevent you from converting the file.

To download the Windows Media Encoder for free, visit the following Microsoft Web site:
http://www.microsoft.com/windows/windowsmedia