Microsoft.Office.Interop.Word.ApplicationClass wordApp = new Microsoft.Office.Interop.Word.ApplicationClass();
object file = path;
object nullobj = System.Reflection.Missing.Value;
Microsoft.Office.Interop.Word.Document doc = wordApp.Documents.Open(ref file, ref nullobj, ref nullobj,
ref nullobj, ref nullobj, ref nullobj,
ref nullobj, ref nullobj, ref nullobj,
ref nullobj, ref nullobj, ref nullobj,
ref nullobj, ref nullobj, ref nullobj,
ref nullobj);
doc.ActiveWindow.Selection.WholeStory();
doc.ActiveWindow.Selection.Copy();
IDataObject data = Clipboard.GetDataObject();
textBox2.Text = data.GetData(DataFormats.Text).ToString();
doc.Close(ref nullobj, ref nullobj, ref nullobj);
wordApp.Quit(ref nullobj, ref nullobj, ref nullobj);