Activating Windows via KMS

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This document should be used as a reference when activating a Windows product using a KMS server.  This document provides step by step instructions on activating a Windows product using a KMS server.

For reference and KMS product keys to be used in KMS product activation, please visit the following site for more information:


In order to active a server via KMS, the following steps must be completed.

First log on to the server and verify that Windows has not been activated.  This can be determined by looking at the activation status show below.


Windows activation status - not activated
Review the activation status to determine if activation is necessary

Once it has been determined that Windows needs to be activated, use the following steps to active using the KMS server.

  •  First the key to be used to active Windows must be set.  It should be assumed that either no key has been entered, or an invalid key was entered and needs to be updated.  If a valid KMS key was used for activation, activation should be automatic.

From the start menu, either search for command prompt or locate it on the start menu and right click it and select the “Run as administrator” option.  This will cause the command window to be run with elevated privileges and is necessary to run the commands needed to activate Windows.

Run as for command prompt
Right click “Command Prompt” and select “Run as administrator” from the popup menu

Once the Command Prompt window is open, enter the following at the prompt.

slmgr /ipk YC6KT-GKW9T-YTKYR-T4X34-R7VHC

This will set the Windows activation key.  NOTE:  A Windows KMS key must be used as retail keys will fail to activate against a KMS server.

command to set Windows key
Enter the vbs command to set the Windows key
Successful key setting results
Popup window displaying the results of the installation of the product key

If the command completes successfully, a window will popup displaying the message “Installed Product Key xxxxx-xxxxx-xxxxx-xxxxx-xxxxx successfully.”, where “xxxxx” is the key entered.

Now that the correct key has been set, all that is left to do is activate Windows.  Using the same Command Prompt window, type the following command.  This will submit the request to active Windows.

command to activate Windows via KMS
Using this command, Windows should be activated using the KMS server

If this is successful, another popup window will be displayed showing the status of the activation as shown below.

successful activation results
Successful activation of Windows

Finally to verify that everything is fully activated, going back to the original window should provide the updated status of the product showing activated.


Windows activation status - activated
Windows is now showing as activated

That is the process for activating via KMS server.

To determine the status of the KMS server, the following command can be run in the same command prompt window using the same slmgr.vbs script, but using the following switches:

slmgr.exe /dlv

This will provide the details of the KMS server including things like number of activations, etc., as shown below.

KMS Server Details Explained
KMS Server Details Explained

If you experience any issues, please see the troubleshooting section below for setting up a KMS server.


KMS activation can only fail for a handful of reasons.  A couple of things to check:

  • DNS entries for the KMS server
  • The KMS key, a specific key is required for KMS activation (see KMS server key used on workstations below)
  • Potentially the Activation key used needs to be “reset”
  • The KMS server has not been properly configured
  • The KMS server has not been fully activated.  This one is strange.  The KMS server will not start accepting activations until a specific number of attempts have been tried

KMS server key used on workstations

Recently, I had the opportunity to work on a KMS environment where the wrong key was used, but the wrong key was used on the clients.  All the clients were built from an image where the KMS server key was used.  When the workstations were deployed into the environment, they all wanted to be KMS servers and advertized themselves via DNS as KMS servers.  This caused some pretty significant chaos as you can imagine.  In order to clean this up, the keys were manually changed on all the workstations, and the DNS entries that had been created were removed.  We were not able to determine a better / automated way to update the keys on the workstations.  It was a time consuming lesson.

Updating / Moving the KMS server

If an existing KMS server is already configured and it needs to be retired or removed, the steps are a little more complicated.  It would be nice if the key could just be changed.  The problem comes in when DNS records are involved and without completely removing the KMS key, the server still wants to publish itself as a KMS server.  The following link provides a step by step process for removing the old server as a KMS server and resetting the KMS key.


Troubleshooting KMS server / client configurations

KMS Client Setup Keys

Removal of old or existing KMS server

Deploying KMS Activation

Volume Activation 2.0 Operations Guide

Last Updated On October 24, 2017