Windows Server: Upgrade Eval to Standard
From wiki.jacobjohns.com
- Once connected to the server start an elevated command prompt.
- Enter the below command.
- dism /online /set-edition:serverstandard /productkey:12345-67890-11121-31415-16171 /accepteula
- DISM will run and request a restart.

- After the restart we are on Windows Server Standard.