Free WMA 2 AAC Converter Pro, as its name, is free and can be used to convert WMA to AAC. It is a good program for you if you want to convert WMA to AAC accidently. It can convert at superfast speed and the converting result is relatively good. The interface is really simple, so it's easy-to-use. You can master it even without any help. It is a professional WMA to AAC converter. Just try it.