private void button1_Click(object sender, EventArgs e)
{
   string urlink = textBox1.Text;
   string dest = Application.StartupPath + "//favicon.ico";
   urlink = urlink.Insert(urlink.Length, "/favicon.ico");
   WebClient webClient = new WebClient();
   webClient.DownloadFile(new Uri(urlink), dest);
   webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
   webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
}
private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
   progressBar1.Value = e.ProgressPercentage;
}
private void Completed(object sender, AsyncCompletedEventArgs e)
{
   MessageBox.Show("Download completed!");
}