As of Windows 2008 R2, ISAPI support is no longer installed by default when Internet Information Services (IIS) is installed. As ISAPI support is required on Windows for WebAccess, Calendar Publishing Host, and Monitor, it needs to be added to IIS before these GroupWise components are installed. If ISAPI is added after the GroupWise components are installed, the individual components will need to be reinstalled. To add ISAPI to IIS after IIS has already been installed, continue with the steps for your operating system below: