Problem with Media Player 11

[thaiink]

I am haveing a problem with wmp 11 when i try to view a movie i purchased off the internet. it is a protected movie and requires me to use the media aquisition rights screen. but when i click on the movie to watct it the MAR does not come up and it only says windows cannot play to file. wmp 11 came with vista on my computer so i cannot uninstall as it is not in the program lists. and i cannot roll back to a previous version. i beleive i need to have a DRMclien.dll and i dont not have that in my system32 folder. without the MAR, i cannot open the movie. does anyone know how to get the usgae rights back on? thanks