(500) Internal Server Error With C# And Web Dev 2008 Express

The code below is generic, found in a variety of places, including a book I have. I have used it as a base for a working program in VS 2005. Now I've resurrected it with my current Visual Web Developer 2008 Express Edition and I seem to have problems connecting it to my default development server (I don't have IIS on my XP). The error is: (500) Internal Server Error. Is this saying what I thought it did (above) or something else, and how do I solve this problem?

using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Net;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text.RegularExpressions;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strResult = "";
string url = "http://weather.unisys.com";
WebResponse objResponse;
WebRequest objRequest;
try
{
objRequest = System.Net.HttpWebRequest.Create(url);
}
catch
{
objRequest = System.Net.HttpWebRequest.Create("http://"+ url);
}
objResponse = objRequest.GetResponse();
using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
{
strResult = sr.ReadToEnd();
sr.Close();
}
}
}