Help please!!!

[Bozo]

Does anyone know how to add music background to a video using windows movie maker?... The problem is I have a voice over audio file running on it, and if I try to add some music to it: it just replaces the voice over audio... I was wondering if anyone knows how to get both the voice over audio and the music to run all at the same time?

http://www.windowsmoviemakers.net/Tutorials/HowToAudioTracks.aspx