title: HTTP Error 500.23 - Internal Server Error Local IIS Web server
body: <p>I am trying to create my async HTTP handler on Visual Studio 2012.
  I have spent about 10 hours to find out why the server keeps giving me "<strong>HTTP Error 500.23 - Internal Server Error</strong>" response. Poor old me.</p>
  
  <p>And finally I found out that if I switch my Web server to Visual Studio Development Server. Everything works fine. And When I switch back to IIS Web server, it doesn't work again.
  I tried to do some configuration with IIS manager. I just have no idea what I should do and how the localhost is linked to my development folder. There is no information about the port it's using and the folder it's mapping.</p>
  
  <p>Can someone offer some help? What should I do to make IIS Web server work for me?
  Thank you</p>