Run DISM /online /Get-CurrentEdition .

– For organizations

DISM /online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

However, if you have a , you can often download the ISO directly from the Microsoft Software Download page by entering your key.

Sign in with an account that has or Key Administrator permissions. Navigate to Billing > Your products > Volume licensing .