Her er et rigtig godt og gratis program som kan converter til utrolig mange formater bla.
Mp3 to Ogg, Mp3 to Wma, Mp3 to AAC, Mp3 to Wav
WAV to Mp3, Wav to Ogg, Wav to AAC, Wav to Wma
Wma to Mp3, Wma to Ogg, Wma to AAC, Wma to Wav
Ogg to Mp3, Ogg to Wma, Ogg to AAC, Ogg to Wav
AAC to Mp3, AAC to Wma, AAC to Ogg, AAC to Wav
Og det er spywarefri (det garanterer Softpedia)
http://www.softpedia.com/get/Multimedia/Audio/Audio-Convertors/Free-Mp3-Wma-Converter.shtml