Before you start
- Open Start and type winver to confirm you are actually running Windows 11 and note the build.
- If Windows came preinstalled, activation is often tied to the device’s digital licence.
Check activation status
Go to Settings > System > Activation and read the Activation state and any displayed error code.
Run the Activation troubleshooter
In Settings > System > Activation, select Troubleshoot if it is offered. Follow the prompts.
After a major hardware change
If you changed the motherboard or other major hardware, use the reactivation path linked from Microsoft’s activation guidance and sign in with the Microsoft account associated with the digital licence.
Product key errors
If a key was already used on too many devices, is for the wrong Windows edition, or is invalid, Windows will not activate. Check the exact error code before buying anything.
Preinstalled licence never activated
If a new PC that shipped with Windows 11 has never activated, contact the PC manufacturer or seller rather than purchasing another key immediately.
Microsoft source
This guide is independently written and condensed from current Microsoft Support guidance. If your Windows build differs or the problem persists, use the official source for the full decision tree.
Open Microsoft Support ↗