Spence, try this; http://download.cnet.com/FormatFactory/3000-2194_4-11114785.html it's Format Factory, will pretty much convert any media into any other type of media. That's an older version, but some of the newer versions has spyware integrated in the installation so I've stuck with the above version. Hope that helps!
Here's the techsupportalert review of several other media converters; http://www.techsupportalert.com/best-free-audio-video-format-conversion-program.htm
I've had no problems with FormatFactory, but maybe better alternatives now...