I downloaded two tracks from www.bignoisemusic.com to put on to my Nomad MuVo not realising they were wma files. Do wma files play on Muvo's? sorry i have lost the packaging and information! the icons for the songs show in the box with my other mp3s but when i play the songs the wma files don't play. I have checked the Rights on the website and it says its ok to download them for portable music players.
Acoustia Mp3 to Wave converter is great. It does WMA , MP3, WAV, and more!
Visit http://www.mp3towave.com/ for information, and the chance to buy it. I'm sure theres a "Trial Version" somewhere too.
dBPowerAmp should also work, but I would have thought it'd be of the two you tried. If you have tried this one (and it failed), maybe you need to download the decode/encode codecs for it (from http://www.dbpoweramp.com/codec-central.htm, last one in Popular Codecs)