uses CommCtrl;

const
  TTS_BALLOON = $40;
  TTI_NONE = 0;
  TTI_INFO = 1;
  TTI_WARNING = 2;
  TTI_ERROR = 3;
  TTM_SETTITLEA = WM_USER + 32;

procedure SetHint(Handle: hWnd; dwIconType: DWORD; lpText, lpTitle: PChar; dwFlags: DWORD = TTS_BALLOON);
var
  TI: TToolInfo;
  trRect: TRect;
  hHint: THandle;
begin
  if (Handle <> 0) and (GetClientRect(Handle, trRect)) then
  begin
    hHint := CreateWindowEx(WS_EX_TOPMOST, TOOLTIPS_CLASS, nil, TTS_NOPREFIX or WS_POPUP or dwFlags,
                            Integer(CW_USEDEFAULT), Integer(CW_USEDEFAULT), Integer(CW_USEDEFAULT), Integer(CW_USEDEFAULT),
                            Handle, 0, hInstance, nil);
    SetWindowPos(hHint, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE or SWP_NOSIZE or SWP_NOACTIVATE);
    ZeroMemory(@TI, sizeof(TToolInfo));
    with TI do
    begin
      cbSize := sizeof(TToolInfo);
      hwnd := Handle;
      uId := Handle;
      hInst := hInstance;
      uFlags := TTF_SUBCLASS or TTF_IDISHWND;
      Rect := trRect;
      lpszText := lpText;
    end;
    SendMessage(hHint, TTM_ADDTOOL, 0, LPARAM(@TI));
    SendMessage(hHint, TTM_SETTITLEA, dwIconType, LPARAM(PChar(lpTitle)));
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  SetHint(Button1.Handle, TTI_INFO, 'My Text ...', 'Info');
end;