JODIX wma-to-mp3 will do it and for multiple files. You will probably have to re-enter and track information other than the title/filename which it copies from the original. But you can usually get the album info/track listings etc using windows media player to access the web. Not sure how your mp3 tracks would change to wma but if they are recently ripped tracks is windows media player set to rip to wma rather than to mp3. Its in Tools, options, rip music.