Use the Add Script Map and Edit Script Map dialog boxes to add new or edit existing native handlers on the Web server. Native handlers, also known as script engines, are native code .exe or .dll files that respond to specific requests.
Script maps provide backward compatibility with earlier versions of IIS. Executables must be written to the CGI specification, and dynamic-link libraries must support the ISAPI extension interfaces.
If you map a type of request to an .exe file (the script engine), CgiModule will load the associated executable when a request enters the server and it matches the handler mapping. If you map a type of request to a .dll file (the script engine), IsapiModule will load the DLL when a request enters the server and it matches the handler mapping. For example, IIS 7 includes a handler mapping for Active Server Pages (ASP). All requests for .asp files are processed by the asp.dll script engine, which is loaded by IsapiModule because ASP.DLL is an ISAPI extension.
If you configure script maps for executables, make sure that CgiModule is registered and enabled on the Modules page. Likewise, if you configure script maps for DLLs, make sure that IsapiModule is registered and enabled on the Modules page.
After you click OK to add or save the handler mapping, the executable must be added to the ISAPI and CGI Restrictions list to enable it to run.
UI Element List
Type a file name extension or file name with an extension for which you want the handler to process requests. For example, if you want the handler to run all requests made for ASP files, enter *.asp; or if you want the handler to run all requests made for a specific file, enter the file name and its extension, such as Myfile.asp.
Type the path to the CGI program or to the ISAPI extension in the physical file system.
Locate the .exe or .dll file in the physical file system.
Type a descriptive name for the handler mapping.
Opens the Request Restrictions dialog box from which you can specify additional, optional restrictions for the mapping.