title: HttpConfiguration missing assembly
body: <p>I am building a site using MVC4. I couldn't even begin that I am having a strange error. This is my code:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Web.Http;
  
  namespace MyProject
  {
      public static class WebApiConfig
      {
          public static void Register(HttpConfiguration config)
          {
              config.Routes.MapHttpRoute(
                  name: "DefaultApi",
                  routeTemplate: "api/{controller}/{id}",
                  defaults: new { id = RouteParameter.Optional }
              );
          }
      }
  }
  </code></pre>
  
  <p>The error message: The type or name of the assembly 'HttpConfiguration' does not exist in the namespace 'System.Web.Http' (are you missing a using directive or an assembly reference?)</p>
  
  <p>It also doesn't recognize the readonly field RouteParameter. It occurs to me that it may have something to do with the version, my System.Web dll is version 4.0.0.0.</p>
  
  <p>Another additional piece of information is that when I type "using System.Web.   ", Intellisense DOES recognize the .Http dll</p>
  
  <p>HOWEVER, in the code, it does not recognize any of its parameters.</p>