Every new generation of the Windows Server operating system includes additional security features and extensions, including for AD. Furthermore, the default settings are made more secure with every new release. Some of them can be used once the new system has been installed, and others only after the domain or forest functional level has been increased. If older operating systems are used as (primary) domain controllers or outdated domain functional levels are used, up-to-date security functions cannot be employed. This increases the threat of insecure default settings. An insecurely configured domain endangers the information processed therein and makes it easier for third parties to carry out attacks.