Installing the ISAPI dispatcher
From the procedures to configure the Microsoft® Internet Information Services (IIS) and install the ISAPI dispatcher within its framework, select the configuration that is right for your system's version of IIS.
For older version of IIS you install it using the Windows® installer. For latest version, IIS is a built-in component of the operating system, you just need to activate it on your system. If you plan to use IIS, install or activate it before running the GAS setup program so that the installation process can complete the web server configuration. To check the installation, or do any additional configuration, select the configuration topic that is right for your system's version of IIS.