終於弄出正確的檢查方式
        //-----------------------------------------------
        //判斷本機是否安裝Excel文件方法
        private bool codeboolisExcelInstalled()
        {
            Type type = Type.GetTypeFromProgID("Excel.Application");
            return type != null;
        }
        private double JongCheckExcelVer()
        {
            Type objExcelType = Type.GetTypeFromProgID("Excel.Application");
            if (objExcelType == null)
            {
                return 0;
            }
            object objApp = Activator.CreateInstance(objExcelType);
            if (objApp == null)
            {
                return 0;
            }
            object objVer = objApp.GetType().InvokeMember("Version", BindingFlags.GetProperty, null, objApp, null);
            double iVer = Convert.ToDouble(objVer.ToString());
            return iVer;
        }
        public String JongGetExcelVerStr()
        {
            String s1;
            double excelver;
            excelver = JongCheckExcelVer();// ExistsExcelRegedit();
            s1 = " Office ";
            if (excelver == 0)
            {
                MessageBox.Show("無法識別Excel的版本", "錯誤", MessageBoxButtons.OK, MessageBoxIcon.Information);
                s1 = "無法識別 office 版本";
            }
            else if (excelver >= 14) s1 += "2010或以上";
            else if (excelver >= 12) s1 += "2007";
            else if (excelver >= 11) s1 += "2003";
            else if (excelver >= 10) s1 += "XP";
            else if (excelver >= 9) s1 += "2000";
            else if (excelver >= 8) s1 += "97";
            else if (excelver >= 7) s1 += "95";
            return s1;
        }
        /*
            if (!codeboolisExcelInstalled())
            {
                MessageBox.Show("Excel不存在", "錯誤", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
            this.Text += JongGetExcelVerStr();
         */