Genghis

hi, through my MSDN subscription i've downloaded the Vista DVD and the
product key for Business edition.
I've now seen that the product key for Ultimate is also available and i'd
like to add DVD Maker to my installation. what do I have to do? i've seen
that there is the anytime upgrade web site but i don't want to buy another
license, i've already have the license key for ultimate.
thanks to all
G