i do believe there is an mplayer binary out there for Windows.... but I can't assure you that it will work.... but probably will.... you probably will need a different command line syntax.... google for "mplayer win32" and of course, google for the companion program, mencoder..... mencoder assembles frames back together

you also might want to see if the win32 version of ImageMagick will rip a frame from an wmv or avi.... its available for Windows too