public void Upload() { string strPathnew = Server.MapPath("~/") + "UploadFile\\AcrTestfinalresult.xls"; try { Excel.Workbook xlWorkBook; Excel.Worksheet xlWorkSheet; xlWorkBook = new Excel.Application().Workbooks.Add(Missing.Value); xlWorkBook.Application.Visible = true; xlWorkSheet = (Excel.Worksheet)xlWorkBook.ActiveSheet; string strPath = Server.MapPath("~/") + "UploadFile\\AcrTestfinal.xls"; StreamReader sr = new StreamReader(strPath); //Read the Excel Stream string strTest = ""; int i = 1; while (!sr.EndOfStream) { strTest = sr.ReadLine(); string[] strData = strTest.Split('\t'); int count = strData.Length; for (int k = 1; k <= count; k++) { string str = strData[k - 1].Replace("\"", ""); if (k == 4) //1 based index of Column required to be changed { str = str.Insert(0, "'"); } xlWorkSheet.Cells[i, k] = str; } i++; } sr.Close(); sr.Dispose(); xlWorkSheet.Columns.AutoFit(); xlWorkBook.SaveAs(strPathnew , Excel.XlFileFormat.xlExcel4, Missing.Value, Missing.Value, false, false, Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value); xlWorkBook.Close(Missing.Value, strPathnew, Missing.Value); } catch { } }