procedure RefreshDesktop;
var
  hDesktop: HWND;
begin
  hDesktop := FindWindowEx(FindWindowEx(
    FindWindow('Progman', 'Program Manager'), 0,
    'SHELLDLL_DefView', ''), 0, 'SysListView32', '');
  PostMessage(hDesktop, WM_KEYDOWN, VK_F5, 0);
  PostMessage(hDesktop, WM_KEYUP, VK_F5, 1 shl 31);
end;