System.Diagnostics.ProcessStartInfo ps = new System.Diagnostics.ProcessStartInfo();
ps.UseShellExecute = true;
ps.Arguments = "C:\\Destination DownloadFile";
ps.FileName = "C:\\Program Files\\WinZip\\WZZIP.EXE";
System.Diagnostics.Process p = System.Diagnostics.Process.Start(ps);
p.WaitForExit();