there are several conversion suites in the software tab above as to which one will do hte wmv files I am not sure as I don't recall ever converting these files personally but I would try divxtodvd (free) as this is one of the most powerfull apps there is plus it's free so you can't lose give it a try. good luck
I agree with I8nights. DivXtoDVD works well with .wmv files. I have the purchased version which is twice as fast as the free version. Worth the money if you plan on doing more than a few. Official guide to the program by Scubapete: http://www.dvdplusvideo.com/petesguide15.html