Does anybody know how to add MP4 functionality to WMP, WMC, and Windows movie maker? I've searched for codecs but. I see a file in the windows folder called mp4 codec and I even ran the program to add it to windows in case it wasn't already and no luck. I am looking for a free solution. I have quicktime and VLC that both play mp4, but I want to add the functionality to Windows itself. I am using Vista64.