Well as you start to get Windows Vista systems in, the question of licensing is going to come up. I've had to do some research on this topic to answer my own questions and now am sharing my results.
In the enterprise you mainly have a choice of either Vista Business or Vista Enterprise. The big difference in Vista Enterprise over Business is that Enterprise will allow you to make up to 3 VM's with the same license on one Vista Machine. Useful for developers!
At any rate you have a choice of licensing Vista with either what is called a Mutilple Access Key(MAK) or setting up your own Key Managment server (KMS) on site. Microsoft tries to explain its Vista licensing for volume activation users a bit at:
Vista can be activated in a few ways. It does this either by contacting Microsoft Servers using the MAK or by contacting a KMS server you have set up in your environment. There is a stipulation about having the ability to have a KMS and it is there must be at least 25 Vista nodes to run it. Obviously if you do not allow internet access to your users your choice is limited to KMS. If you have less than 25 machines in your Office and don't allow internet access you probably will be SOL after a few months until you connect to the MAK and activate your licences. : (
KMS Vista activated machines must call home to the KMS server at least every 6 months. If you are using MAK you only need to connect 1 time to the Microsoft servers for activation, the machines will not have to be reactivated. There is a good guide to licensing Vista at:
Anyways the whole point of my article here is the rumour going around I have been getting told is that a Vista KMS can only be run on either a Vista Machine or on Server 2008 (formerly code named Longhorn and still not available yet!). This is not the case though!
Microsoft in March of this year released Key Management Server software that WILL run on Windows Server 2003 SP1 or later Servers. You can go out and get it now from:
You will also want to have a look at the Windows Vista Volume Activation Technical guide which also has included a web page you can set up to recover licenses that have gone into Reduced Functionality Mode (RFM) (go read up on that one!) Check it out at:
Hope this gets a few of your questions answered about Windows Vista Volume licensing and gets you pointed in the right direction to get started as Windows Vista Systems will be coming your way sooner than later!