If you have Microsoft Zune player and ever wanted to play your purchased music on any other players, here is the solution.
FairUse4WM - a WM/DRM removal program
Here is brief summary of this program could do.
... a new tool for uncovering the individual keys from Microsoft's DRM blackbox components ("IBX"), up to version 11.0.6000.6324. Lacking the source code to the extant programs
....This version should be capable of interfacing with both Windows Vista and Zune software versions.
Have fun and Enjoy your music!