HTTP Error 403.14 - Forbidden

I am learning 

http://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api

download the project from

http://code.msdn.microsoft.com/ASP-NET-Web-API-Tutorial-8d2588b1

but when i run the project i get following error

HTTP Error 403.14 - Forbidden

The Web server is configured to not list the contents of this directory.

below is snap shot of it

http://postimg.org/image/ygrq712np/

I am using windows7 

how to fix it