New Post: How open a Workbook without Events enabled.

pExcel = new Excel.ApplicationClass();
pExcel.EnableEvents = false;   
pExcel.Visible = pvisible;
pBooks = pExcel.Workbooks;
pBook = null;
pBook = pBooks.Open(pNomArchivo, pMissing, pMissing,
                pMissing, pMissing, pMissing, pMissing, pMissing, pMissing,
                pMissing, pMissing, pMissing, pMissing, pMissing, pMissing);