Activation error

0xC004F039

Key Management Service (KMS) not enabled

A Windows PC set up as a KMS client sent an activation request to a Key Management Service host and got no answer. Microsoft points to the network connection between the two, in particular TCP port 1688. Lizensa supplies retail keys and MAKs, not KMS keys, and does not run KMS for customers.

Symptoms

Activation fails with "The Software Protection Service reported that the computer couldn't be activated. The Key Management Service (KMS) isn't enabled."
The PC is set up as a KMS client, so it asks a KMS host for activation

Causes

The KMS host did not respond to the KMS request
A firewall blocks or filters TCP port 1688, the default KMS port, between the client and the KMS host

How to fix it

Company device: check the path to the KMS host

Microsoft's fix is to troubleshoot the network connection between the KMS host and the client and to make sure no firewall blocks or filters TCP port 1688. On a work PC, ask your IT department to check this.

MAK from Lizensa: install it in place of the KMS client key

Volume licensing editions of Windows are KMS clients by default. For computers that cannot use KMS activation, Microsoft documents changing the product key to a MAK. Open Command Prompt with Run as administrator and enter your MAK in place of the placeholder.

slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

Try activation again

After installing your MAK, start online activation and read the message that the window shows.

slmgr /ato

Display the licence information

This shows the licence information for the installed Windows edition, so you can check the result.

slmgr /dli

KMS or your own key?

KMS is how organisations activate many PCs on their own network: a KMS host activates the clients. If you installed Windows Enterprise, an LTSC edition or Windows Pro from volume media, it may still use the generic KMS client key. The steps above replace it with your MAK.

With a retail key, follow the Settings path in Activate Windows 11 or Activate Windows 10. The command-line route and telephone activation for MAKs are in the volume key sections of the same guides: Windows 11, Windows 10. How many PCs a MAK covers is explained in How MAK activation limits work.

When to contact Lizensa support

Contact our support if your key from Lizensa is installed and activation still fails, or reports a different code. Send your order number, the last five characters of the key and the exact error message.

Still need help?

If error 0xC004F039 keeps blocking activation after these steps, our support team can check your key and license channel directly.

Contact support

Genuine licenses

Genuine licenses that activate cleanly

Windows 10 Pro MAK

€89.00

Windows 11 Enterprise

€39.90

Windows 11 Enterprise LTSC 2024

€49.90

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