Baixar arquivo de Site Direto no Csharp com windowsforms

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using System.Net;

namespace AlexSystemsBackup.Frms
{
    public partial class FrmDownloadsFile : Form
    {

        string  sourcePath = Environment.CurrentDirectory + "\\",
                StrSiteDonloads = "http://the.earth.li/~sgtatham/putty/latest/x86/pscp.exe", 
                StrArquivoSalvar = "pscp.exe";

        public FrmDownloadsFile()
        {
            InitializeComponent();
        }

        private void FrmDownloadsFile_Load(object sender, EventArgs e)
        {
            try
            {
                string Strarquivobaixado = sourcePath + StrArquivoSalvar;
                MessageBox.Show("baixando arquivo " + StrSiteDonloads + " -> " + Strarquivobaixado);

                WebClient webClient = new WebClient();
                webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completo);
                webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressoFeito);
                webClient.DownloadFileAsync(new Uri(StrSiteDonloads), Strarquivobaixado);
            }
            catch (Exception error)
            {
                MessageBox.Show("Error ao baixar arquivo -> " + error);
            }
        }
        private void ProgressoFeito(object sender, DownloadProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage;
        }

        private void Completo(object sender, AsyncCompletedEventArgs e)
        {
            MessageBox.Show("Download efetuado!");
        }

    }
}