Windows Server 2003
Windows Server 2003 (sometimes informally referred to as Win2K3, or just 2K3) is a server operating system produced by Microsoft and released on April 24, 2003. It was a successor of Windows 2000 Server and incorporated some of Windows XP features. An updated version, Windows Server 2003 R2, was released to manufacturing on December 6, 2005. Its successor, Windows Server 2008, was released on February 4, 2008. Windows Server 2003's kernel was later adopted in the development of Windows Vista.
Overview
Windows Server 2003 was the follow-up to Windows 2000 Server, incorporating compatibility and other features from Windows XP. Unlike Windows 2000 Server, Windows Server 2003's default installation has none of the server components enabled, to reduce the attack surface of new machines. Windows Server 2003 includes compatibility modes to allow older applications to run with greater stability. It was made more compatible with Windows NT 4.0 domain-based networking. Incorporating and upgrading a Windows NT 4.0 domain to Windows 2000 was considered difficult and time-consuming, and generally was considered an all-or-nothing upgrade, particularly when dealing with Active Directory. Windows Server 2003 brought in enhanced Active Directory compatibility, and better deployment support, to ease the transition from Windows NT 4.0 to Windows Server 2003 and Windows XP Professional.