As with Windows Vista, Windows Server 2008 is available in several different product editions. These editions support different hardware platforms (32-bit x86, 64-bit x64, and Itanium), some of which include support for the Hyper-V
virtualization technologies and some that do not. (Note that Hyper-V is only enabled on x64 versions of Windows Server 2008.)

Windows Web Server 2008
Availability: Separate 32-bit (x86) and 64-bit (x64) versions
Pricing: $469
Supported processors: four
Supported RAM: 4GB (x86) or 32GB (x64)
Notes: Windows Web Server is designed specifically around the Web Server role and cannot be used as an Active Directory (AD) domain controller (DC). (It can, however, be configured as a domain member.) This version doesn’t include Hyper-V but does support Server Core installations.

Windows Server 2008 Standard, Windows Server 2008 Standard without Hyper-V
Availability: Separate 32-bit (x86), 64-bit (x64), and 64-bit (x64) without
Hyper-V versions
Pricing: $999 (with five Client Access Licenses—CALs); $971 without
Hyper-V
Supported processors: four
Supported RAM: 4GB (x86) or 32GB (x64)
Notes: Includes one virtual instance per license.

Windows Server 2008 Enterprise, Windows Server 2008 Enterprise without Hyper-V
Availability: Separate 32-bit (x86), 64-bit (x64), and 64-bit (x64) without
Hyper-V versions
Pricing: $3,999 (with 25 CALs); $3,971 without Hyper-V
Supported processors: eight
Supported RAM: 64GB (x86) or 2TB (x64)
Notes: Includes four virtual instances per license. Builds on Standard Edition and adds Windows Clustering.

Windows Server 2008 Datacenter, Windows Server 2008 Datacenter without Hyper-V
Availability: Separate 32-bit (x86), 64-bit (x64), and 64-bit (x64) without
Hyper-V versions
Pricing: $2,999 per processor; $2,971 per processor without Hyper-V
Supported processors: 32 (x86) or 64 (x64)
Supported RAM: 64GB (x86) or 2TB (x64)
Notes: Includes unlimited virtual instances per license. Builds on Enterprise Edition.

Windows Server 2008 for Itanium-based Systems
Availability: A single 64-bit version designed for Intel Itanium-based servers Pricing: $2,999 per processor
Supported processors: 64
Supported RAM: 64GB
Notes: This version of Server 2008 doesn’t support Hyper-V or Server Core and is designed for three discrete usage scenarios: Large databases, lineof-business (LOB) applications, and custom applications.

Microsoft Hyper-V Server
Availability: A single 64-bit (x64) version
Pricing: $28 (no, that’s not a typo)
Notes: The new Hyper-V Server is a special version of Server 2008 that supports only the Hyper-V role, providing a near bare-metal installation option for those who wish to run extensively virtualized environments. This version of the product won’t ship until later in 2008.

In addition to these products, Microsoft recently announced that two new Server 2008-based products will debut in the second half of 2008. These products are Windows Small Business Server (SBS) 2008 and Windows Essentials Business Server 2008.

SBS 2008, code-named Cougar, is aimed at businesses with up to 50 PCs. It will ship in two versions, one of which includes Server 2008, Microsoft Exchange Server 2007, Windows SharePoint Services 3.0, and one-year trial subscriptions to Microsoft Forefront Security for Exchange Server Small Business Edition and the new Windows Live OneCare for Windows Server. SBS 2008 Premium adds a second copy of Server 2008 (32-bit or 64-bit) and Microsoft SQL Server 2008 Standard Edition (32-bit or 64-bit) and can be installed on a second server.

SBS 2008 Standard will cost $1,089 with five CALs, while individual CAL costs fall from $100 to $77. The Premium edition will cost $1,899 with five CALs. A new Premium CAL is $189. Both of these products are bit more expensive than their predecessors, but because of the individual CAL price drop, and the ability to buy CALs individually for the first time, the overall cost of SBS should be cheaper for most customers.

Windows Essential Business Server 2008, previously code-named Centro, is a new product aimed at mid-sized businesses with up to 250 desktops. This product is installed on three separate servers and includes Server 2008, Exchange Server 2007, Forefront Security for Exchange Server, Microsoft System Center Essentials (SCE) 2007, and the next version of Microsoft ISA. The Premium edition of the product will also include SQL Server 2008. Essential Server requires four physical servers.

Essential Business Server 2008 Standard will retail for $5,427 with CALs costing $81; the standalone cost of the bundled products is about $7,799, Microsoft says. Meanwhile, Essential Business Server 2008 Premium is $7,163, with CALs costing $195 each. The standalone cost of the bundled products in that edition is about $10,213. Essential Business Server 2008 products will be sold only in 64-bit (x64) versions (aside from the secondary servers in SBS 2008 Premium).