If you install Office Communications Server 2007 R2 on a computer running IIS 7.0 on Windows Server 2008, you need to configure IIS to run in IIS 6.0 compatibility mode. You need to install all of the following IIS services:

• ASP.NET
  
  

• Windows Authentication
  
  
• IIS 6 Management Compatibility
  
  

This group of services for IIS 6 Management Compatibility includes the following:

• IIS 6 Metabase Compatibility
  
  
• IIS 6 WMI Compatibility
  
  
• IIS 6 Scripting Tools
  
  
• IIS 6 Management Console
  
  

When you install and activate Office Communications Server 2007 R2 on a computer running Windows Server 2008, Setup disables kernel mode authentication in IIS to support Kerberos. As an alternative to disabling kernel mode authentication, you can configure IIS to use the Web application pools identity for internal virtual directories used by Office Communications Server. For details, see Internet Information Services (IIS) 7.0 Kernel Mode Authentication Settingsin the Administering Office Communications Server 2007 R2 documentation.