Windows Live Movie Maker can output video in the format required by the importer of video content in XNA. That is, the WLMM saves the video as Windows Media Video 9 "Main" using the VC-1 video codec and the Windows Media Audio 9.2 audio codec. You still need to make sure that you do not go beyond the transfer speed, as indicated here , but if you use "Burn a DVD", the settings when saving your movie, you should be fine if you do 480p.
NB: , . , XNA . , WAV , .