According to Microsoft, Windows Server 2003 is more scalable and delivers better performance than its predecessor, Windows 2000.
Released on April 24, 2003] Windows Server 2003 (which carries the version number 5.2) is 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.
Changes to various services include those to the IIS web server, which was almost completely rewritten to improve performance and security, Distributed File System, which now supports hosting multiple DFS roots on a single server, Terminal Server, Active Directory, Print Server, and a number of other areas. Windows Server 2003 was also the first operating system released by Microsoft after the announcement of their Trustworthy Computing initiative, and as a result, contains a number of changes to security defaults and practices.
The product went through several name changes during the course of development. When first announced in 2000, it was known by its codename, "Whistler Server"; it was then named "Windows 2002 Server" for a brief time in mid-2001, before being renamed "Windows .NET Server" as part of Microsoft's effort to promote their new integrated enterprise and development framework, Microsoft .NET. It was later renamed to "Windows .NET Server 2003". Due to fears of confusing the market about what ".NET" represents and responding to criticism, Microsoft removed .NET from the name during the Release Candidate stage in late-2002. This allowed the name .NET to exclusively apply to the .NET Framework, as previously it had appeared that .NET was just a tag for a generation of Microsoft products.
About Enterprise 2003:
Windows Server 2003, Enterprise Edition is aimed towards medium to large businesses. It is a full-function server operating system that supports up to eight processors and provides enterprise-class features such as eight-node clustering using Microsoft Cluster Server (MSCS) software and support for up to 32 GB of memory through PAE (added with the /PAE boot string). Enterprise Edition also comes in 64-bit versions for the Itanium and x64 architectures. Both 32-bit and 64-bit versions support Non-Uniform Memory Access (NUMA). It also provides the ability to hot-add supported hardware..
# Internet Information Services (IIS) v6.0 - A significantly improved version of IIS.
# Increased default security over previous versions, due to the built-in firewall and having most services disabled by default.
# Significant improvements to Message Queuing.
# Manage Your Server - a role management administrative tool that allows an administrator to choose what functionality the server should provide.
# Improvements to Active Directory, such as the ability to deactivate classes from the schema, or to run multiple instances of the directory server (ADAM)
# Improvements to Group Policy handling and administration
# Improved disk management, including the ability to back up from shadows of files, allowing the backup of open files.
# Improved scripting and command line tools, which are part of Microsoft's initiative to bring a complete command shell to the next version of Windows.
# Support for a hardware-based "watchdog timer", which can restart the server if the operating system does not respond within a certain amount of time.
About Server 2003 Release 2 (R2)
Windows Server 2003 R2, an update of Windows Server 2003, was released to manufacturing on December 6, 2005. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003. The R2 update was released for all x86 and x64 versions, but not for Itanium versions.
* Branch Office Server Management
o Centralized management tools for file and printers
o Enhanced Distributed File System (DFS) namespace management interface
o More efficient WAN data replication with Remote Differential Compression.
* Identity and Access Management
o Extranet Single Sign-On and identity federation
o Centralized administration of extranet application access
o Automated disabling of extranet access based on Active Directory account information
o User access logging
o Cross-platform web Single Sign-On and password synchronization using Network Information Service (NIS)
* Storage Management
o File Server Resource Manager (storage utilization reporting)
o Enhanced quota management
o File screening limits files types allowed
o Storage Manager for Storage Area Networks (SAN) (storage array configuration)
* Server Virtualization
o A new licensing policy allows up to 4 virtual instances on Enterprise Edition and Unlimited on Datacenter Edition
* Utilities and SDK for UNIX-Based Applications add-on, giving a relatively full Unix development environment.
o Base Utilities
o SVR-5 Utilities
o Base SDK
o GNU SDK
o GNU Utilities
o Perl 5
o Visual Studio Debugger Add-in
computer and processor- 133-MHz or faster processor for x86-based PCs; 733-MHz for Itanium-based PCs; up to eight processors supported on either the 32-bit or the 64-bit version
Memory- 128 MB of RAM minimum required; maximum: 32 GB for x86-based PCs with the 32-bit version and 64 GB for Itanium-based PCs with the 64-bit version
Hard disk- 1.5 GB of available hard-disk space for x86-based PCs; 2 GB for Itanium-based PCs; additional space is required if installing over a network
Drive -CD-ROM or DVD-ROM drive
Display -VGA or hardware that supports console redirection required
Other- Windows Server 2003 Enterprise Edition, 64-bit version is compatible only with 64-bit Intel Itanium-based systems and cannot install on 32-bit systems