How to activate Windows 11: a step-by-step guide

Have a Windows 11 licence key but not sure where to enter it? Activation takes less than a minute. Below are two methods — through Settings and via the command line — plus fixes for the most common errors.

Before you start: what you need

• An activation key — a 25-character code (XXXXX-XXXXX-XXXXX-XXXXX-XXXXX). If you bought from us, it arrives by email.
• An internet connection — activation goes through Microsoft servers.
• A Microsoft account — optional but recommended: a licence linked to it is easier to restore after a hardware change.

Activation through Settings (the simplest way)

1. Go to Start → Settings (or press Windows + I).
2. Go to System → Activation on your keyboard).
3. Next to “Activation state”, click Change product key .
4. Enter the 25-character key. You do not need to type the dashes — they are added automatically.
5. Go to Next → Activate. After a few seconds you will see “Windows is activated”.

Activation via the command line

If Settings does not work, try this method. Open Command Prompt as administrator (Start → type “cmd” → right-click → Run as administrator) and enter these commands:

Common errors and what to do

Error 0xC004C003 — “The activation server determined the key is blocked”

Usually means the key has already been used on another computer, or the server is temporarily unavailable. Wait an hour and try again. If it repeats, contact your seller.

Error 0xC004F050 — “The product key is invalid”

Almost always a mismatch between the key and the installed edition: a Home key will not activate Pro, and vice versa. Check which edition is installed (Settings → System → About).

Error 0x803FA067 — activation after a hardware change

After replacing the motherboard, Windows often loses the licence. If you were signed in with a Microsoft account, the Troubleshooter helps: Settings → Activation → Troubleshoot → “I changed hardware on this device recently”.

How to check whether Windows is activated

Open Settings → System → Activation. The message “Windows is activated with a digital licence” or “…with a product key” means everything is fine. A quick check: press Windows + R, type winver and press Enter.