>You mean i need .net interop DLLs. But i open it , i saw two Microsoft.Office.Interop.Excel version 11 or 12. >After i add the Microsoft.Office.Interop.Excel version 12. and run program . > >In this code, Sheet.Range("C" & iRow).Value = "AAA" will error. > >COMException was unhandled >HRESULT: 0x80020011 (DISP_E_NOTACOLLECTION))