Activate Windows with a valid product key
Sign in with the Microsoft account linked to your digital license
Run Windows Activation Troubleshooter
Check that your Windows edition matches your license
Enter the correct product key in Settings > System > Activation
Contact Microsoft Support if your license is valid but activation fails
Replace the motherboard or other hardware only after confirming license transfer eligibility
Reinstall Windows using the correct edition if it was installed incorrectly
Avoid unofficial activation tools or cracks