Configuring ISAPI and CGI Restrictions in IIS 7
Applies To: Windows 7, Windows Server 2008, Windows Server 2008 R2, Windows Vista
ISAPI and CGI restrictions are request handlers that allow dynamic content to execute on a server. These restrictions are either CGI files (.exe) or ISAPI extensions (.dll). You can add custom ISAPI or CGI restrictions if the IIS configuration system allows this.
For information about the levels at which you can perform these procedures, and the modules, handlers, and permissions that are required to perform these procedures, see ISAPI and CGI Restrictions Feature Requirements (IIS 7).