I have the same problem and have been messing with it for 3 days. It all seems related to the fact that you cannot install Windows Media Foundation (which contains the required codecs to play WMV and WMA and so on).
This morning I found the following: http://www.microsoft.com/downloads/d...c-a6cef9b414c4
It was just released yesterday. I can only assume that a whole lot of people were complaining.
I myself just wanted to have a system without WMP interfering with everything, not a windows that is crippled by removing support for pretty much any media format except for WAVs....
Edit: I suppose it will work, am still downloading it myself, but because this forum/topic helped me on my quest I though I'd share