Microsoft has increased the number of versions of Windows Server 2003 it offers. Microsoft offered Windows 2000 in three editions: Server, Advanced Server, and Datacenter Server, each requiring increasingly faster processors and more memory. Windows Server 2003 is available in the following editions:
This version of Windows Server 2003 is optimized to host web sites using IIS and is therefore limited in its support of hardware and in its feature set. It cuts the addressable memory in half from 4GB to 2GB, restricts Internet Connection Sharing, network bridging, and Terminal Services (although you can use the XP-like Remote Desktop), and does away with DHCP and fax services. In addition, WE can be a member server of a domain, but it cannot be an Active Directory domain controller. Windows Server 2003 WE is available only through OEMs; you can’t purchase it through traditional retail channels.
This is the plain-vanilla version of Windows that most corporations likely will deploy. Included with it is support for up to two processors and 4GB of memory. SE includes most of the features and support of the other editions, including the .NET Framework, IIS 6, Active Directory, the distributed and encrypting filesystems, and various management tools. You also receive Network Load Balancing (a feature previously reserved for the “premium editions” of the NT server product) and a simple Post Office Protocol 3 (POP3) server which, coupled with the existing Simple Mail Transfer Protocol (SMTP) server bundled with IIS, can turn your Windows Server 2003 machine into an Internet mail server.
Aimed squarely at more demanding environments, EE adds Metadirectory Services support, high-level memory management features, and some session management features for Terminal Services. It also includes support for eight-node clustering and booting directly from a SAN. Plus, you can add memory to EE while the system is running, without needing to reboot.
This performance- and scalability-enhanced Windows Server 2003 edition supports from 8 to 32 processors and features 64GB of memory and from two to eight node clusters. With the exception of more extensive firewalling features, DE is identical to EE. You can obtain DE only on a Microsoft-certified computer preinstalled by the OEM, much like the Web Edition.
For some time now, this flavor of Windows Server 2003 has been available as the only 64-bit Windows operating system. Recently, Microsoft added support for Intel’s second-generation Itanium 2. This version isn’t as well known as its more common cousins, largely because the OS and the hardware necessary to run it are unavailable through most channels—this version of Windows comes bundled with 64-bit hardware available for only a handful of manufacturers. Microsoft eventually plans to migrate this release into the naming structure of the other Windows Server 2003 editions.