I know how to play them but to convert not so sure. AFAIK they are simply an mpeg 4 variation, so there should be a no. of converters with the ability to convert such files. To play, I'd recommend this player: VLC - (click on link) _ (choose nearest mirror site). BTW I'm not sure why anybody would want to convert a file to wmv format, but that's their choice. And a loss of quality due to the conversion process.