Запись в файл Microsoft Word (2003,2007)

//using Word = Microsoft.Office.Interop.Word;

Word.Application ap = new Word.Application();
try
{

    Word.Document doc = ap.Documents.Open(@"D:\MyWord.doc", ReadOnly: false, Visible: false);
    doc.Activate();

    Word.Selection sel = ap.Selection;

    if (sel != null)
    {
        switch (sel.Type)
        {
            case Word.WdSelectionType.wdSelectionIP:
                sel.TypeText(DateTime.Now.ToString());
                sel.TypeParagraph();
                sel.TypeText("Microsoft Word");
                sel.TypeParagraph();
                break;

            default:
                Console.WriteLine("Selection type not handled; no writing done");
                break;

        }

        // Remove all meta data.
        doc.RemoveDocumentInformation(Word.WdRemoveDocInfoType.wdRDIAll);

        ap.Documents.Save(NoPrompt: true, OriginalFormat: true);
    }
    else
    {
        Console.WriteLine("Unable to acquire Selection...no writing to document done..");
    }

    ap.Documents.Close(SaveChanges: false, OriginalFormat: false, RouteDocument: false);
}
catch (Exception ex)
{
    Console.WriteLine("Exception Caught: " + ex.Message); // Could be that the document is already open (/) or Word is in Memory(?)
}
finally
{    
    ((Word._Application)ap).Quit(SaveChanges: false, OriginalFormat: false, RouteDocument: false);
    System.Runtime.InteropServices.Marshal.ReleaseComObject(ap);
}

Результат: