: You can enter a genuine product key by going to Settings > Update & Security > Activation > Change product key .

: If you previously had Windows 7, 8, or 10 on your device, the license is often tied to your hardware or Microsoft account. Windows may auto-activate once you sign in.

Activation of Windows 10 through "cracks" or unofficial activators is as these tools often contain malware, disable critical security features, and violate Microsoft's Terms of Service.

: Organizations use official KMS client keys provided by Microsoft for volume licensing. 2. Legal Free Options