FeyConverter is an audio toolkit which can convert files between formats, for instance (file types supported include MP3, MP4/M4A, Ogg Vorbis, AAC, Bonk and FLAC), rip CDs, create playlists and more.
And getting started with this seems easy enough. You can add files directly from a folder, or rip them from a CD, and both functions leave you with a list of tunes which you can review and play.
After that, things become a little more complicated than they need to be. There's no wizard here to walk you through the process of, say, converting a bunch of MP3's to WMA. Instead you'll find an MP3 encoder selected by default.
Explore the menus and you'll find an Encode > Start Encoding option which lists a bunch of supported formats, so you might think choosing the WMA option would ask you for any relevant settings. But no, it just starts encoding immediately.
Click Stop, and you can then use another option to view and configure the results you need. The program offers plenty of control here, at least, and when you're done, restarting the job will convert the files for you. (Although by default it'll dump them into a Documents\FeyConverter folder, which probably isn't what you need.)
There is useful functionality here, then, but the program's less than intuitive interface means you may not have the time or patience to figure out how to access it.
Please note, the program will by default install the "NetScout Toolbar" as well as its own code. If you don't want this, choose the Custom Installation option during setup and clear the relevant checkboxes.