Users assigned the Administrator role for an object are allowed to view and perform all actions on the object. This role also includes all permissions inherent in the Read Only role.

If you are acting in the Administrator role on an ESX host, you can grant permissions to individual users and groups on that host. If you are acting in the Administrator role in vCenter Server, you can grant permissions to any user or group included in the Windows domain list that vCenter Server references.

vCenter Server registers any selected Windows domain user or group through the process of assigning permissions. By default, all users who are members of the local Windows Administrators group on vCenter Server are granted the same access rights as any user assigned to the Administrator role. Users who are members of the Administrators group can log in as individuals and have full access.

Users who are in the Active Directory group ESX Admins are automatically assigned the Administrator role.

For security reasons, consider removing the Windows Administrators group from the Administrator role. You can change permissions after installation. Alternately, you can use the vSphere Client to delete the Windows Administrators group access permissions, but you must first create another permission at the root level that has a different user assigned to the Administrator role.