Last year I blogged about using server side includes in web pages. My SSI code has all been working well on my ISP’s Apache servers, but my development server runs under IIS 5 on Windows 2000. Even with the default document list set to include index.shtml, I was getting HTTP 404 errors for pages that I knew existed. I checked that I had application mappings in place for .shtml files, but what none of the documentation told me was that I needed to change the executable path for .shtml from %systemroot%\System32\inetsrv\404.dll to %systemroot%\System32\inetsrv\ssinc.dll. Once I had made that change, everything jumped into life and my dynamic pages were served as expected.