Task: Enter in the Exchange Product Key in Exchange Powershell by using the command below.
Set-ExchangeServer servername –ProductKey aaaaa-aaaaa-aaaaa-aaaaa-aaaaa
Even though you can see the new edition on Exchange, the new edition/product key will not be fully activated until the Information Store service is restarted. The new editions functionality will not be there until the service restart. Restart it from Exchange Powershell Below.