August 8 2011

KMS host server won’t activate clients

Our KMS server had been running without issue for months until recently when I tried to activate another Windows Server 2008 R2 client (already 30+ in the environment) and it just wouldn’t activate, giving the error “”Error: 0xC004F074 The Software Licensing Service reported that the computer could not be activated. The Key Management Service (KMS) is unavailable”.”.

I decided to reinstall the KMS host key on the KMS server and tried to re-activate using “slmgr -ato”, however this gave an error also – “The activation server determined that the specified product key could not be used.” After doing some googling and spending hours trying to get some Microsoft help, it appears that there are limits on the number of times a KMS host can be activated (although the error message was completely useless and didn’t even remotely hint that this was the problem).

Anyway, in short – the solution was to email Microsoft via with:

  • KMS host key
  • Organisation name
  • Enrollment number
  • Number of additional activations you would like

Within about 2 business days Microsoft responded with “As requested, the number of KMS activations has been increased. The additional KMS host activations have been added to our production environment and are available for use. We appreciate your patience while we worked to fulfill your request.”

I then ran tried to re-activate using “slmgr -ato” on the KMS server – this time it was successful and the KMS clients could once again activate against the KMS host.


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June 2 2009

Change Product Key On Windows Server 2008

Open the command prompt and navigate to %windir%System32 directory

slmgr.vbs -cpky (this clears the KMS entry you may have)
slmgr.vbs -upk (this removes any product key installed)
slmgr.vbs -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx (where the x’s are the new product key you want to use)
slmgr.vbs -ato (this activates the server)

Type slmgr.vbs for further options….

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