Windows 7 got error. Net framework application 4.0 (written with WinXP SP3)

Question

What am I doing wrong? I have application, which run normally, but when I press button in Win 7 (search in Google) that assigns

hl.NavigateUri = new Uri("http://www.google.com.ua/#hl=ru&source=hp&biw=1280&bih=933&q=");

it Crashes. What am I doing wrong? On Windows XP SP3 machine it normally works..

private void button1_Click(object sender, RoutedEventArgs e)
{
    try
    {
        bool google = true;

        if (((Button)sender).Content.ToString() == "Google")
            google = true;
        else
            google = false;
        Run run1 = new Run(textBox1.Text);
        Hyperlink hl = new Hyperlink(run1);
        TextBlock tb = new TextBlock();
        //Label label1 = new Label();
        //label1.Content = textBox1.Text;
        //label1.Tag = ;
        if (google)
            hl.NavigateUri = new Uri("http://www.google.com.ua/#hl=ru&source=hp&biw=1280&bih=933&q=");
        else
            hl.NavigateUri = new Uri("http://yandex.ua/yandsearch?text=");
        hl.Tag = i;
        hl.Click += new RoutedEventHandler(hl_Click);
        tb.Inlines.Add(hl);
        tb.Inlines.Add(" ");
        wrapPanel1.Children.Add(tb);
        if (google)
        {
            col1_links.Add("http://www.google.com.ua/#hl=ru&source=hp&biw=1280&bih=933&q=" + HttpUtility.UrlEncode(textBox1.Text));
        }
        else
        {
            col1_links.Add("http://yandex.ua/yandsearch?text=" + HttpUtility.UrlEncode(textBox1.Text));
        }
        col1_texts.Add(textBox1.Text);
        webBrowser1.Navigate(col1_links[i].ToString());
        i++;
        SaveData();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

I got the following error:

Answer 1

I can rewrite your code in a few lines:

private void button1_Click(object sender, RoutedEventArgs e)
{
    try
    {
        var google = ((Button)sender).Content.ToString() == "Google";
        var run1 = new Run(textBox1.Text);
        var hl = new Hyperlink(run1)
        {
            NavigateUrl = google ? "http://www.google.com.ua/#hl=ru&source=hp&biw=1280&bih=933&q=" :
                                   "http://yandex.ua/yandsearch?text=";
            Tag = i;
        };
        var tb = new TextBlock();
        hl.Click += new RoutedEventHandler(hl_Click);
        tb.Inlines.Add(hl);
        tb.Inlines.Add(" ");
        wrapPanel1.Children.Add(tb);
        col1_links.Add(hl.NavigateUrl + HttpUtility.UrlEncode(textBox1.Text));
        col1_texts.Add(textBox1.Text);
        webBrowser1.Navigate(col1_links[i].ToString());
        i++;
        SaveData();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

Try to be more professional ;) . First of all, NavigateUrl is "string" (not Uri), try to use this (not NavigateUri). Second thing is there is no "i" variable, where is it?