how to load webpage using c#

IDE: VS 2010, C# .net 4.0

Hi,

I am trying to open oneplus invite page using following way:

private void btnOpenPage_Click(object sender, EventArgs e)
    {

        LoadPage();

    }

 private void LoadPage()
    {
        WebBrowser webBrowser1 = new WebBrowser();

        webBrowser1.Navigate("http://ift.tt/1D10dJZ");

        //Wait for document to load...
        while (webBrowser1.ReadyState != WebBrowserReadyState.Complete)
        {
            Application.DoEvents();
        }

        //Set the text of the search input

        string htmlText = webBrowser1.DocumentText;

        using (StreamWriter file = new StreamWriter(@"D:\oneplus.htm",false))
        {
            file.Write(htmlText);
        }

        Process.Start(@"D:\oneplus.htm");

As this page is opening in Chrome and firefox, but I am not able to load it in programmatically, also this page is not able to open in Internet Explorer.

So guys, can you help me to open this page programmatically.