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The quickest way to activate Windows 11 is in Settings: open Settings → System → Activation, select Change product key, enter your 25-character key and select Activate. This guide covers every way to do it, how to upgrade Home to Pro, what to do after a reinstall or a new motherboard, and what the common error codes mean.
Before you start: check your edition
Open Settings → System → About and look at Edition. A Windows 11 Home key activates Home and a Pro key activates Pro. If your PC runs Home and you have a Pro key, follow the Home to Pro steps further down.
To see whether Windows is already activated, open Settings → System → Activation. Active means you are done. Not active means Windows needs a key.
Activate Windows 11 with a product key
- Connect the PC to the internet.
- Press Windows + I to open Settings, then go to System → Activation.
- Next to Change product key, select Change.
- Type or paste your 25-character product key and select Next.
- Select Activate. After a few seconds the status changes to Active.
Activate during installation
When Windows 11 setup asks for a product key, enter it there and Windows activates as soon as the PC is online. If you don’t have the key yet, choose I don’t have a product key and activate later in Settings. On a PC that was activated before, install the same edition and Windows activates by itself.
Activate with Command Prompt
Search for cmd, right-click Command Prompt and choose Run as administrator. Then run these two commands, with your own key in the first one:
slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
slmgr /atoThe first command installs the key and the second one activates it. To check the result, run slmgr /xpr.
Activate by phone
Phone-activation keys don’t activate online: Windows shows an error such as 0xC004C008 and offers phone activation instead. That is expected. Follow our phone activation guide; you get the Confirmation ID from our Get CID page, with no call needed.
Upgrade Windows 11 Home to Pro
Open Settings → System → Activation, select Change product key and enter a Windows 11 Pro key. Windows adds the Pro features and restarts; your files and apps stay where they are.
Use a Pro Retail key for this. MAK (volume) keys can’t upgrade Home to Pro. Microsoft also sells the upgrade in the Microsoft Store app.
After a reinstall or a hardware change
- Reinstalling on the same PC: Windows remembers the PC (a digital license). Install the same edition, connect to the internet and it activates by itself.
- New motherboard or new PC with a Retail key: sign in to Windows with your Microsoft account, then go to Settings → System → Activation → Troubleshoot → I changed hardware on this device recently.
- OEM keys stay with the first PC’s motherboard. A new PC needs a new key.
Common Windows 11 activation errors
| Error | What it means | What to do |
|---|---|---|
| 0xC004C003 | The activation server says the key is blocked or not valid. | Check the key for typos. If it still fails, ask the seller for a replacement. |
| 0xC004C008 | The key has reached its limit for online activation. | For a phone-activation key this is normal: activate by phone. Otherwise contact the seller. |
| 0xC004F213 | Windows found no license for this PC, usually after a hardware change. | Run the activation troubleshooter, or enter your key again. |
| 0x803FA067 | No valid license for the edition you’re activating, often when upgrading Home to Pro with the wrong type of key. | Use a Pro Retail key, on a PC that runs Windows 11 Home. |
| 0x8007232B, 0xC004F074 | Windows is looking for a company activation server (KMS). | Enter your own key with slmgr /ipk, then run slmgr /ato. |
Bought your key from Keys Locker? If it doesn’t activate within the warranty shown on the product page, message us from your order page and we send a replacement or a refund.
Check that Windows 11 is activated
Settings → System → Activation should say Active. In Command Prompt, slmgr /xpr opens a window that says the machine is permanently activated.