Visual studio 2010 vs visual studio express (visual web developer 2010)

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C#

i have installed visual studio 2010 and made half of my project in it. Now i was reading about mvc, in that i was asked to install visual studio express and then visual web developer 2010.
My query is that if i install visual web developer will it work with my previously installed visual studio 2010. or my whole work will be damaged?
what should i do? i dont want my project to be damaged and i also want to learn mvc .
Is visual studio express 2010 work within the visual studio 2010 like the ajax tools?

I dont know what to do.. any suggestions??

What I have tried:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MvcApplication1.Controllers
{
[HandleError]
public class HomeController : Controller
{
public ActionResult Index()
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";

return View();
}

public ActionResult About()
{
return View();
}
}
}