Before you start
- Edition must match. A Home key activates Home; a Pro key activates Pro or upgrades Home to Pro. Check your edition.
- Be online. Activation contacts Microsoft's servers.
- Use an administrator account. Standard accounts can't change the product key.
- Have the 25 characters ready. Keys are in the form XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Copy and paste it from your purchase confirmation to avoid typos.
Method 1: Settings
- Open Settings (Windows + I).
- Go to System › Activation.
- Next to Change product key, select Change. Confirm the User Account Control prompt.
- Enter the key. Hyphens are added automatically.
- Select Next, then Activate.
You'll see Windows is activated when it succeeds. If you entered a Pro key on Home, Windows first prepares the upgrade and restarts; activation completes after the restart. See Home to Pro upgrade.
Method 2: Command line
Useful if Settings won't open the key dialog. Right-click Start, choose Terminal (Admin), and run:
slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
Wait for the confirmation, then run:
slmgr /ato
To check the result, run slmgr /xpr. It should report that the machine is permanently activated.
Method 3: During a clean installation
Windows 11 Setup asks for a product key early on. You can enter it there, or select I don't have a product key, choose the matching edition, and activate from Settings later. If you skip the key, be sure to choose the edition your key is for, because Setup installs whatever you pick.
If the PC can't go online
On supported Windows builds, you can also try slui 4 for phone/offline activation: run it in an admin Terminal, choose your country, and follow the prompts to read out an installation ID and type back a confirmation ID. On newer builds where that option is unavailable, use the Windows Activation troubleshooter or Microsoft's activation support options.
After activation
Windows creates a digital license for the PC. If you sign in with a Microsoft account as an administrator, the license is linked to that account, which helps reactivation after a hardware change. Settings › System › Activation will say Windows is activated with a digital license linked to your Microsoft account.
If it doesn't activate
- The key is rejected or "doesn't work": Windows 11 product key not working.
- You see an error code such as 0xC004F050 or 0x803F7001: Windows 11 activation errors.
- You recently replaced the motherboard: activation after hardware changes.