Windows Server 2008 is Microsoft's last 32-bit server operating system. While it was initially planned to be released to manufacturing by the end of 2007, Microsoft pushed back the RTM date for Windows Server 2008, formerly codenamed Longhorn, to early 2008 due to quality issues. At this point in time, the product is still planned for release at the end of February 2008, with Windows Vista Service Pack 1 to follow. At the end of September, almost concomitantly with the availability of Windows Vista SP1 Beta, Microsoft also dropped the latest development milestone for Windows Server 2008.

From Windows Server 2003 R2 Standard Edition, Windows Server 2003 Standard Edition SP1, Windows Server 2003 Standard Edition SP2 and Windows Server 2008 Standard Beta 3, users will be able to move to a full installation of Windows Server 2008 Standard or Enterprise. At the same time, running Windows Server 2003 R2 Enterprise Edition, Windows Server 2003 Enterprise Edition SP1, Windows Server 2003 Enterprise Edition SP2 and Windows Server 2008 Enterprise Beta 3 will permit upgrades to Windows Server 2008 Enterprise. And last, exactly the same is valid for all the Datacenter editions of Windows Server 2003 and 2008, and upgrades to Windows Server 2008 Datacenter.

"Upgrading from Windows Server 2003 to Server Core installations of Windows Server 2008 is not supported. You cannot uninstall this version of Windows Server 2008 if you have installed it as an upgrade. However, if Setup fails, you can roll back to your previous operating system. In the Setup Wizard, once you have selected the edition and chosen the option to upgrade (instead of performing a clean installation), you will be presented with a dialog box that includes a link to application compatibility information. Be sure to follow the link and review the information about your installed applications before you proceed with the upgrade", Microsoft added.