Need help burning wmv files to DVD with nero startsmart

I made a movie with windows movie maker, and saved it with the default filetype, i think it’s wmv, and then I went onto nero, and went to the photo and video tab, then burn dvd-video files. the popup box thing where you put your files came up, and I tried to drop and drag my file on there, and it came up with 'no compatible file found'. does this mean I need to use a diferent file type? if so, how do I save it as a diferent file type?
thanks,
E.J

I ususlly use the imtoo dvd creator, I feel better, maybe you also need it, here is the link: http://www.imtoo.com/dvd-creator.html