Use Native Module instead of ISAPI on IIS 7.x except for Universal Web Gateway which requires ISAPI. To use ISAPI on IIS ...

Use Native Module instead of ISAPI on IIS 7.x except for Universal Web Gateway which requires ISAPI.

To use ISAPI on IIS 7.x for Universal Web Gateway, the ISAPI Extension, ISAPI Filter, and IIS Management Scripts and Tools role services must be installed.

To install these role services, choose Add Role Services under the Web Server (IIS) role in Server Manager.  Check the ISAPI Extension, ISAPI Filter, and IIS Management Scripts and Tools items if not already checked.  Follow the remaining prompts to complete the install.