Answer - Windows 2003 Active Directory introduced a number of new security features, as well as convenience features such as the ability to rename a domain controller and even an entire domain Windows Server 2003 also introduced numerous changes to the default settings that can be affected by Group Policy - you can see a detailed list of each available setting and which OS is required to support it by downloading the Group Policy Settings Reference. ADS stands for Automated Deployment Services, and is used to quickly roll out identically-configured servers in large-scale enterprise environments. You can get more information from the ADS homepage.