The preview is available to MSDN and TechNET subscribers as well as Connect customers. Windows Server 2008 is expected to be released to manufacturing by the end of 2007.
Microsoft announced at TechEd last month that IIS 7.0 would become the ninth server role available as a Server Core minimal install option. Server Core allows IT managers to install only the bare bones OS components needed to run a server role.
The eight other server roles that will be available in Server Core are File Server, print, Active Directory, Active Directory Lightweight Edition, Windows Media Services, DHCP, DNS and virtualization.
Microsoft also said it is working toward adding the .Net Framework as a Server Core role to get more functionality out of the IIS 7.0 in Server Core, such as the ability to use scripting language PowerShell, said Ward Ralston, a product manager with Microsoft's Windows Server team.
More than 200,000 testers have downloaded Windows Server 2008 Beta 3 since it was released in April, Microsoft said.