uses 
  ComObj; 

function ConvertDoc2Rtf(var FileName: string) : Boolean;
var 
  oWord: OleVariant; 
  oDoc: OleVariant; 
begin 
  Result := False; 
  try 
    oWord := GetActiveOleObject('Word.Application'); 
  except 
    oWord := CreateOleObject('Word.Application'); 
  end; 
  oWord.Documents.Open(FileName); 
  oDoc  := oWord.ActiveDocument; 
  FileName := ChangeFileExt(FileName, '.rtf'); 
  oDoc.SaveAs(FileName); 
  oWord.ActiveDocument.Close(wdDoNotSaveChanges, EmptyParam, EmptyParam); 
  oWord.Quit(EmptyParam, EmptyParam, EmptyParam); 
  oDoc := VarNull; 
  oWord := VarNull; 
  Result := True; 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
const 
  FileName = 'c:\Document.doc'; 
begin 
  if ConvertDoc2Rtf(FileName) then 
  begin 
    ShowMessage('Word document has been converted to .rtf'); 
    RichEdit1.Lines.LoadFromFile(FileName); 
  end; 
end;