9. August 2019
- Open the Settings app and click Update & Security.
- Open Activation and click Change product key.
- Enter your Windows 10 Professional product key and click Next.
- Restart the computer after the new product key is activated.
You can force a downgrade with the default product key (VK7JG-NPHTM-C97JM-9MPGT-3V66T) of Windows 10 Professional.