Try with below code:
string Path = @"E:\documents\Data20160129110355.xls";
string sFileName = "Data20160129110355.xls";
Response.Clear();
HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition", "attachment; filename=" + sFileName);
HttpContext.Current.Response.RedirectLocation = url;
HttpContext.Current.Response.TransmitFile(Path);
HttpContext.Current.Response.Flush();
HttpContext.Current.Response.Close();