Select Start > Settings > Update & Security > Activation , and then select Troubleshoot to run the Activation troubleshooter. For more info about the troubleshooter, see Using the Activation troubleshooter.

Why is my Windows activation key not working?

If your activation key isn’t working, you might be able to fix the problem by resetting the license status. After running the command, close Command Prompt and restart your PC. Once your PC restarts, try to activate Windows again.

Why is my Windows 10 suddenly not activated?

If your genuine and activated Windows 10 also became not activated suddenly, don’t panic. Just ignore the activation message. … Once Microsoft activation servers become available again, the error message will go away and your Windows 10 copy will be activated automatically.