Remember that the UserAssist keys are encrypted with ROT13?
The Vigenère key I found through some basic cryptanalysis is BWHQNKTEZYFSLMRGXADUJOPIVC.
To the Microsoft developer who designed this: great joke! You really made me laugh. Seriously. 8-)
And I thought Easter Eggs were banned in Microsoft products. Maybe you don’t think of it as an Easter Egg, but as a programmer, I do. ;-)