Unable to run web application for .Net framework 2.0, 3.5 in IIS 7.5

From my experience with ASP.NET MVC, I've seen that a Default.aspx page is required for IIS to function correctly. I'm using the page that was included in the ASP.NET MVC 1 template. Unfortunately, the ASP.NET MVC 2 does not include this page (to the best of my knowledge), so you should add the following to your project:

Default.aspx:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="YourNamespace._Default" %>

<%-- Please do not delete this file. It is used to ensure that ASP.NET MVC is activated by IIS when a user makes a "/" request to the server. --%>

Default.aspx.cs:

using System.Web;
using System.Web.Mvc;
using System.Web.UI;

namespace YourNamespace
{
    public partial class _Default : Page
    {
        public void Page_Load(object sender, System.EventArgs e)
        {
            // Change the current path so that the Routing handler can correctly interpret
            // the request, then restore the original path so that the OutputCache module
            // can correctly process the response (if caching is enabled).

            string originalPath = Request.Path;
            HttpContext.Current.RewritePath(Request.ApplicationPath, false);
            IHttpHandler httpHandler = new MvcHttpHandler();
            httpHandler.ProcessRequest(HttpContext.Current);
            HttpContext.Current.RewritePath(originalPath, false);
        }
    }
}

By default, Windows 7 and Windows Server 2008 comes with .net 2.0 and .net 3.5. Remember even though you have .net framework 3.5 the CLR version is 2.0. There is no CLR v3.5. You can always host .net 3.5 related applications on the server where your web.config file will be referencing the necessary namespaces.

From the article .NET Framework 3.5 Architecture

The architecture of the .NET Framework version 3.5 and 3.5 Service Pack 1 (SP1) builds upon the earlier versions of the .NET Framework.

An application uses the same assemblies regardless of whether it targets the .NET Framework version 2.0, 3.0, 3.5, or the Client Profile, and regardless of whether the assemblies have been updated on a user's computer. For example, an application that uses Windows Presentation Foundation (WPF) and targets the .NET Framework 3.0 uses the same instance of the mscorlib assembly as an application that uses Windows Forms and targets the .NET Framework 2.0.