Convert mp4 files for editing in Windows MovieMaker

[tasmade]

How can I convert uploaded mp4 files from my pocketPC into a format (.avi?) that I can load into MovieMaker to edit. I tried a freeware converter called mp4conv2AVI which was a superb little utility, but Moviemaker tells me the codecs could not be downloaded when I try to import the converted .avi's. (I have the auto download option checked in MovieMaker).
Any advice appreciated

[tasmade]

How can I convert uploaded mp4 files from my pocketPC into a format (.avi?) that I can load into MovieMaker to edit. I tried a freeware converter called mp4conv2AVI which was a superb little utility, but Moviemaker tells me the codecs could not be downloaded when I try to import the converted .avi's. (I have the auto download option checked in MovieMaker).
Any advice appreciated