Does anyone know how to import tracks from Movie Maker to Audacity, remove unwanted noise (I have been able to to this part) and then move the repaired track back to Windows MM? 
what is the format of tracks in MM
where does MM keep them
if you can find the track
move a copy to a working folder
and than convert (if necessary) to an audacity usable format
then you could drag and drop that file to the audacity program
to get it opened
then process it
and
reverse ALL the steps to put it back in MM’s folder with its right format and extension
Audacity version 1.3 will import the audio from video files (including WMV) if you have downloaded and installed the ffmpeg import/export library. version 1.2 will not.
The current release is 1.3.11, which you can get from here
http://audacityteam.org/download
and the directions to download and install ffmpeg are here
http://manual.audacityteam.org/index.php?title=FAQ:Installation_and_Plug-Ins#installffmpeg
In addition, the noise reduction tools are much better in 1.3 than 1.2.
Once you’ve finished editing, export the audio in a format that WMM recognises (you can export as WMA when you have ffmpeg installed).
PO’L