How to Activate Windows 11 Pro with a Product Key

A Windows 11 Pro product key is 25 characters long, written in five groups of five: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Activation takes about a minute once you have it. This guide covers both ways to do it and how to confirm it worked.

Before you start

• Check which edition is installed. Open Settings → System → About and look at "Edition". A Windows 11 Pro key will not activate a machine running Windows 11 Home — but it will upgrade it, which is covered below.
• Be connected to the internet. Online activation contacts Microsoft's activation servers directly.
• Copy the key rather than retyping it. Most rejected keys are typing mistakes. The letters O and I never appear in Microsoft keys — if you see them, they are the digits 0 and 1.

Method 1: activate through Settings

• Open Settings (Windows key + I).
• Go to System → Activation.
• Expand Change product key and click Change.
• Paste your 25-character key and click Next.
• Click Activate and wait for the confirmation.

If your PC currently runs Windows 11 Home and you enter a Pro key here, Windows offers to upgrade the edition instead. Accept it — the upgrade keeps your files and installed programs, and the PC restarts once when it finishes.

Method 2: activate from the command line

This is the faster route if Settings refuses to open the activation panel, and it gives you a clearer error message when something is wrong.

• Right-click Start and choose Terminal (Admin) or Command Prompt (Admin).
• Install the key: slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
• Activate it: slmgr /ato

Each command opens a small dialog box with the result. If activation fails, that box shows an error code — write it down, it tells you exactly what went wrong.

Confirm that activation worked

Go to Settings → System → Activation. The status should read Active. For the full licence details, run slmgr /xpr in a command prompt — it states whether the machine is permanently activated.

If the key is rejected

Work through these in order:

• Wrong edition. A Pro key on a Home installation, or a Windows 10 key on Windows 11, produces an immediate rejection. Check Settings → System → About.
• A character was mistyped. Paste the key rather than typing it.
• No internet connection. Activation needs to reach Microsoft's servers; a captive-portal Wi-Fi network or a strict corporate firewall can block it.
• An error code appeared. Look it up in our guide to Windows activation error codes — each one has a specific cause.

Still stuck? Contact us with your order number and the exact error code, and we will sort it out.