Windows Server 2003 builds upon a lot of the technology in Windows NT 4.0 and introduces a more reliable platform with features designed to make managing the server environment simpler and reducing the total cost of ownership.

One of the first benefits that can be achieved by upgrading from Windows NT 4.0 to Windows Server 2003 is Active Directory. Active Directory greatly simplifies the administration of network objects. It provides a central location for managing objects such as computers and user accounts, making the management of network resources simpler and less time consuming. Container objects such as organizational units can be created and network objects grouped in such a way that best meets the administrative needs of an organization. Not only does this make administration simpler but it also makes it easier for users to locate information on the network.

Windows Server 2003 is also far more scalable than Windows NT 4.0. It can be scaled as an organization grows, unlike Windows NT which is limited in its scalability. If you recall from NT 4.0, the SAM database is limited to 40 MB. Once the limit is reached performance begins to degrade. The only way to over come the limitation is to create another domain. Windows Server 2003, on the other hand, allows you to literally store millions of objects within a single domain.

Windows Server 2003 is capable of distributing network and management resources much more efficiently that Windows NT. One important change from Windows NT Server 4.0 is that there is no longer one server (the primary domain controller) maintaining the only working copy of account and security information. In Windows Server 2003, there are no primary domain controllers or backup domain controllers. Multiple servers can be designated as domain controllers, each containing a copy of Active Directory.

Windows Server 2003 supports the Distributed File Service (Dfs) which allows files, folders and resources stored on different servers throughout the network to appear as a single tree structure for easier access.

Windows Server 2003 uses Kerberos as the default authentication protocol. Kerberos is a security system that enables you to securely communicate over a network. Kerberos works through a special communications protocol that enables a client to initiate contact with a server and request secure communication. The server responds by providing an encryption key that is unique to that communication session, and it does so by using a protected communication called a ticket. Kerberos is more secure than NTLM, the authentication protocol used in Windows NT.

The Microsoft Management Console (MMC) provides one of the most powerful and consistent management interfaces. The MMC is a management tool can be customized by adding in the “snap-in” you want to work with, which can be installed or removed at will. The benefit of this is that all management functions can be performed from a single interface, unlike Windows NT where management tasks have to be performed in different places.