Not sure if you've read this already, but a new free program called Fairuse4wm has been released on the Internet, which allows you to remove protection from WMA DRM 10 and 11 licensed files, thereby removing limits of DRM. There are other such tools, but this one has worked for me.
When you first run the program, it will require you to load one WMA DRM protected file with an active license key. Following that, you can add any WMA DRM protected file to remove the DRM protection.
All the original WMA DRM protected files must have active licenses on your PC for the program to be able to remove the DRM protection.
Tested, and works. The program doesn't do any encoding, so the original audio quality is retained. It simply removes the DRM protection. At the moment, Fairuse4wm is obtainable from Softpedia and other mirrors are currently available on the Internet. Microsoft are yet to respond, but chances are that the tool won't survive for long on the Internet.
More information from the following article:
http://www.engadget.com/2006/08/25/fairuse4wm-strips-windows-media-drm/
