how to solve this error "Exception from HRESULT: 0x800A03EC"?

[STAThread]

       protected void Generate_Click(object sender, EventArgs e)
        {
            int io = 0;
            System.Data.DataTable workTable = new System.Data.DataTable();
            workTable.TableName = "VendorList";
            workTable.Columns.Add("CURRENCY_CODE");
            workTable.Columns.Add("REMARKS");
            workTable.Columns.Add("VENDOR_NAME");
            System.Data.DataRow workRow;
            objDAOUploadEnquiry.ActionType = SRCMAction.FETCH.ToString();
            objBLLUploadEnquiry.SelectCommonMasterUom(objDAOUploadEnquiry);
            object dropDownValues = "";
            for (int y = 0; y <= 9; y++)
            {
                workRow = workTable.NewRow();
                //workRow[0] = "Cust" + y.ToString();// y;
                //workRow[1] = "Cust" + y.ToString();
                if (io == 0)
                {
                    for (int kl = 0; kl < objDAOUploadEnquiry.UploadEnquriyList.Rows.Count; kl++)
                    {
                        dropDownValues += objDAOUploadEnquiry.UploadEnquriyList.Rows[kl]["TEXT_VALUE"].ToString() + ",";
                    }
                    io = 1;
                }
                workTable.Rows.Add(workRow);
            }

            string data = null;
            int i = 0;
            int j = 0;
            int rowsCount = workTable.Rows.Count + 1;

            Excel.Application xlApp;

            Excel.Workbook xlWorkBook;

            Excel.Worksheet xlWorkSheet;

            object misValue = System.Reflection.Missing.Value;
            object pwd = "pwd";
            Excel.Application xl = null;

            Excel._Workbook wb = null;

            Excel._Worksheet sheet = null;

            object Missing = System.Reflection.Missing.Value;

            try
            {

                xlApp = new Excel.ApplicationClass();
                xl = new Excel.Application();

                xlWorkBook = xlApp.Workbooks.Add(misValue);
                xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
                wb = (Excel._Workbook)(xl.Workbooks.Add(Missing));
                wb.Sheets.Add(Missing, Missing, Missing, Missing);
                sheet = (Excel._Worksheet)(wb.Sheets[1]);
                xlWorkSheet.Name = "IncludeVendorList";
                Excel.Range m_range = sheet.get_Range("A1", "A10");
                //sheet.get_Range("A1", "A11").Font.Color  = System .Drawing .Color .Red ;





                Excel.Range _nValidationRange = xlApp.get_Range("C2", "C10");

<code>I got an error on the Following Line While i execute this code </code>
                _nValidationRange.Validation.Add(Excel.XlDVType.xlValidateList, Excel.XlDVAlertStyle.xlValidAlertStop, Excel.XlFormatConditionOperator.xlBetween, dropDownValues, Type.Missing);
                xlWorkBook.SaveAs(("G:\\dhinakr.xls"), Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);



                xlWorkBook.Save();
                xlApp.Quit();
                xlApp.Application.Quit();
                string filepath = "G:\\dhinakr.xls";
                FileInfo myfile = new FileInfo(filepath);
                if (myfile.Exists)
                {
                    Response.ClearContent();
                    Response.ContentType = "application/vnd.ms-excel";
                    Response.AppendHeader("Content-Disposition", "attachment; filename=" + myfile.Name);
                    Response.AddHeader("Content-Length", myfile.Length.ToString());
                    Response.TransmitFile(myfile.FullName);

                    Response.End();
                }
            }
            catch (COMException Ex)
            {
                GC.Collect();
                throw new Exception(Ex.Message);
            }
        }