procedure TForm1.DisableFontSmoothing(LabelName: TLabel);
var
  tagLOGFONT: TLogFont;
begin
  GetObject(LabelName.Font.Handle, SizeOf(TLogFont), @tagLOGFONT);
  tagLOGFONT.lfQuality  := NONANTIALIASED_QUALITY;
  LabelName.Font.Handle := CreateFontIndirect(tagLOGFONT);
end;
 
//Example Use for Label2
procedure TForm1.Button1Click(Sender: TObject);
begin
  DisableFontSmoothing(Label2);
end;