There are lots of softwares that do this job.
Just write mp32wma in google or something like that and you?ll be on your way.
My mp3 player can play both mp3 and wma files. The file capacity is doubled if I store them in wma format. Is wma has a smaller file size thus more compressed than mp3 but the quality has not been adversely compromised? My files are all mp3. How can I convert them to wma?