You've bought a huge can of worms. If you are planning to do some substantial volumes of upgrades, then you will need to read the paperwork very carefully and

You've bought a huge can of worms. If you are planning to do some substantial volumes of upgrades, then you will need to read the paperwork very carefully and then use that knowledge to negotiate very hard. I've been involved in several such situations and in every case the responsible account executives would come up with wildly inconsistent interpretations and numerous retractions. Unless you represent a substantial value deal and are prepared to dump M$ for open source alternatives, you are not likely to have much joy. Sometimes dealing with systems integrators (resellers) is more lucrative.