For new installations (not upgrades) EFT Server (both editions) queries the computer’s local administrators group and adds that group to EFT Server’s administrator account name list with the one local administrator group object, and assigns the administrator group object Server-level permissions. The Local computer\Administrators group object allows you to log in to EFT Server using the administrator credentials for the local computer. You cannot change the group's permissions when you are logged in as a user in that group.
Refer to Active Directory-Based Administration for more information about accessing EFT Server using the Active Directory accounts.
Refer to Adding Server Administrators for details of creating an EFT Server administrator account that uses AD-based authentication.