Saturday, January 15, 2011

KMS Minimum Clients (Activation Thresholds)

I came across this issue during the week when I was reading into KMS licensing in a bit of detail and thought it might be something worth sharing as I hadn't realised there were a minimum number of activations required for KMS to operate. Here's the official text from Microsoft's website on the subject:

KMS requires a minimum number of either physical or virtual computers in a network environment. These minimums, called activation thresholds, are set so that they are easily met by enterprise customers.

For computers running:
  • Windows Server 2008 and Windows Server 2008 R2 you must have at least five (5) computers to activate.

  • Windows Vista or Windows 7 you must have at least twenty-five (25) computers to activate.

  • For Office 2010, Project 2010 and Visio 2010 you must have at least five (5) computers to activate. If you have deployed Microsoft Office 2010 products, including Project 2010 and Visio 2010, you must have at least five (5) computers running Office 2010, Project 2010 or Visio 2010.


  1. You mention:
    'These thresholds can be a mix of server and client machines to make up the threshold number.'
    Does this mean if I have 10 x Server 2008 R2 activation's, i would only need 15 x windows 7 activation's?

  2. Hi and thanks for the comment!

    Since I've posted the article above, I've come across a lot more information about KMS.

    To answer your question, you cannot have a mixture of servers and clients to reach one threshold type. The mixture allowed is related to clients of different KMS aware client O/S or else (not as well as) Servers of different KMS aware server O/S.

    See the link below for more information:

    I've also amended my post above to stop any further confusion!