Solving Windows Activation Error using SLMGR

Slmgr.vbs is an inbuilt software utility in Windows which is used to configure volume editions of Windows client and server operating systems, and Key Management Service (KMS) hosts. Ospp.vbs, which is used to configure volume editions of Office 2010 client products.

After building a new Windows Operating System Server or Client machine, you might face issues with the Activation. There could be many reason responsible for it like KMS Server not reachable or KMS Server not configured on client OS. Upon login you might also receive following errors.


If your KMS Server is not reachable you probably need to check firewall on the client machine or the Network Related components but if the KMS Server is not configured properly here the steps to configure it.


  • Open an elevated command prompt

  • In the command line type slmgr /ato
    (This command will try to automate the Activation process. If it succeeds you will get a popup stating that Product activated successfully.


  • If the KMS is not working, you will receive an error stating The Key Management Service (KMS) is unavailable.

  • Now, if you want to check your current KMS Server, you can use the command slmgr /dlv. It will give you all the details in a popup window.

  • Now if you noticed that your KMS Server is not the correct one, it can be changed easily. The command to change the KMS server is slmgr /skms
    (your KMS Server Name)

  • After changing the KMS Server details and getting the confirmation for the changes you just need to run following command once more : slmgr /ato
  • It will automate the activation process again and should activate you windows if the KMS Server is the correct one.


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