Activate Windows and fix activation errors

Windows has to be activated after installation. Until that has happened, the system still runs, but it shows a watermark and locks parts of the personalisation. This guide shows you how to enter the key, check the status and make sense of typical error messages.

Checking the activation status

1. Open Settings with the Windows key and I.
2. On Windows 11, go to System → Activation; on Windows 10, to Update & Security → Activation.
3. There you can see whether Windows is activated and which edition is installed.

Entering the licence key

1. On the activation page, click Change product key.
2. Enter the 25-character key. It is best to copy it straight from the email to avoid typing errors.
3. Click Next and then Activate.
4. The computer has to be connected to the internet while you do this.
5. Then check the status again on the same page.

Activating from the Command Prompt

If the interface will not co-operate, you can also do it with commands. Open the Command Prompt as an administrator (Start menu, type cmd, Run as administrator):

1. slmgr /ipk YOUR-KEY enters the key.
2. slmgr /ato starts the activation against the Microsoft servers.
3. slmgr /dlv shows detailed licence information, including the licence type.
4. slmgr /xpr shows whether the activation is permanent or has an expiry date.

Each of these appears as a small dialog box. With a volume licence, slmgr /dlv shows a reference to a KMS or MAK channel; with a retail licence it says Retail.

Retail, OEM and volume licences

The licence type determines what happens when the hardware changes. A Retail licence is not permanently tied to a particular motherboard. An OEM licence comes from a complete device and is tied to its hardware; after a motherboard swap, activation there usually fails. Volume licences activate either against a KMS server on the network or once, with a MAK key, against the Microsoft servers. The output of slmgr /dlv tells you which one you have.

Common error codes

0xC004C003	The server rejected the key, often because it is already in use on another device or because the server is under heavy load.
0xC004F050	The key does not match the installed edition – for example a Pro key with the Home edition installed.
0xC004F074	No activation server could be reached – typical of KMS licences with no connection to the server, or when the system time is wrong.
0x803FA067	The activation could not be completed; often seen after a hardware change.
0x8007232B	DNS name does not exist – this occurs when a volume key is used without a reachable KMS server.

If something goes wrong

• Check the edition: A key for Windows 11 Pro will not activate a Home installation. You can see the edition under Settings → System → About.
• Use the troubleshooter: The activation page has a Troubleshoot option that resolves many cases automatically.
• Check the system time: A wrong time or time zone makes the activation fail.
• After a hardware change: Sign in with the Microsoft account the computer was previously linked to and use the troubleshooter option for a device change.
• Check the network: Firewalls or proxies on company networks occasionally block activation. Another connection or a mobile connection will tell you whether that is the cause.
• Try more than once: When the servers are busy, it often helps to try again a few hours later.

If an error code persists, write to us via the contact page. Give your order number, Windows edition and the error code word for word.