Как долго запущена Windows?

Code:

function UpTime: string;

const

  ticksperday: Integer    = 1000 * 60 * 60 * 24;

  ticksperhour: Integer   = 1000 * 60 * 60;

  ticksperminute: Integer = 1000 * 60;

  tickspersecond: Integer = 1000;

var

  t:          Longword;

  d, h, m, s: Integer;

begin

  t := GetTickCount;

  d := t div ticksperday;

  Dec(t, d * ticksperday);

  h := t div ticksperhour;

  Dec(t, h * ticksperhour);

  m := t div ticksperminute;

  Dec(t, m * ticksperminute);

  s := t div tickspersecond;

  Result := 'Uptime: ' + IntToStr(d) + ' Days ' + IntToStr(h) + ' Hours ' + IntToStr(m) +

    ' Minutes ' + IntToStr(s) + ' Seconds';

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

  label1.Caption := UpTime;

end;