public DataTable ReadExcel (string Pach, string ListName)
        {           
        DataTable DT = new DataTable();
        if (ListName == null) { return DT; }
        OleDbConnection MyConnection; 
        DataSet DtSet; 
        OleDbDataAdapter MyAdapter; 
        MyConnection = new OleDbConnection(@"provider=Microsoft.Jet.OLEDB.4.0;Data Source='"+ Pach+"';Extended Properties=Excel 8.0;");
        MyAdapter = new OleDbDataAdapter("select * from ["+ListName+"]", MyConnection);
        MyAdapter.TableMappings.Add("Table", ""+ListName+"");
        DtSet = new DataSet();
        MyAdapter.Fill(DtSet);
        DT = DtSet.Tables[0].Copy();
        DtSet.Clear();
        MyConnection.Close();
        return DT;
        }

...
MyConnection = new OleDbConnection(@"provider=Microsoft.Jet.OLEDB.4.0;Data Source='" + Pach + "';Extended Properties=Excel 8.0; IMEX=1");
...