A genuine key must satisfy complex mathematical rules embedded in the Windows operating system core.
Genuine Windows 7 product keys are structured in a specific pattern ( XXXXX-XXXXX-XXXXX-XXXXX-XXXXX ). These unique strings cannot be guessed by random generation software. Why "Product Key Makers" Do Not Work windows 7 product key maker
If your Windows 7 installation is currently running but shows a "Not Genuine" message after a reinstallation, your original key might still be encrypted inside the registry database. You can view it manually: Press Win + R , type regedit , and hit . A genuine key must satisfy complex mathematical rules