Installing Windows Server 2019, the product key is required during installation,however if you are waiting for licensing to arrive , you can skip this and continue installation of server, Once you received the licensing, Now you will need to enter the product key from the settings app. But clicking “Change Product Key ” button the windows did not pop up.
Here how to resolved the issue no need to reformat or reloading Windows again.
1. Click Start and type CMD in the Start Search menu
2. Right Click and choose Run as administrator.
3. To remove any existing product key (in case you used a trial key), enter and run the command slmgr.vbs /upk .
4. Clear the product key from registry by running slmgr.vbs /cpky
5. To enter your new product key, use the command: slmgr.vbs /ipk AAAAA-AAAAA-AAAAA-AAAAA where the A’s are your actual product key.
6. Lastly, activate Windows by entering the command slmgr.vbs /ato
WINDOWS NOW IS ACTIVATED.