Changing the Product Key on Windows Server

Occasionally, it may be necessary to change the product key on a server.  For example, if you have built the server using a development product key and now want to licence it properly with a customers licence.

Once you have licenced the server however, the option to enter a product key goes away, and there is no obvious way to get it back.  You could rebuild the server from scratch, but this seems overkill.

Alternatively:

• Open a command prompt and change working directory to system32 directory (or ensure the system32 directory is in the path)
• Type slmgr.vbs -ckms (this will remove any KMS entry)
• Type slmgr.vbs -upk (this will remove the current product key)
• Type slmgr.vbs -ipk <product key> (where <product-key> is the new product key you want to use, and is in the following format: xxxxx-xxxxx-xxxxx-xxxxx-xxxxx)
• Type slmgr.vbs -ato (for CORE servers.  This activates server, an Internet connection is required)
  Alternatively type slui which will open the usual activation GUI.

This process has been tested on Windows Server 2008, 2008 R2 and 2012 R2.