[s0Creator]

а может так?

Код:

procedure TForm1.Button6Click(Sender: TObject);
var
  x, w, curent : hwnd;
begin
  x:=FindWindow('WindowsForms10.Window.8.app3', nil);
  w := 0;
  while true do
  begin
    w:=FindWindowEx(x, w, 'WindowsForms10.SysListView32.app3', nil) ;
    if w = 0 then
      break;

    //edit1.Text:=trim(copy(IntToStr(w), 0, 9));
    if IsWindowVisible(w) then 
      EnableWindow(w, True);
  end;

end;

или вообще все дочернии

Код:

function WinEnable(WinHandle: HWnd; lParam: LPARAM): Boolean; stdcall;
begin
  Result:=True;
  if IsWindowVisible(WinHandle) then
    EnableWindow(WinHandle, True);
end;

procedure TForm1.Button6Click(Sender: TObject);
var
  x, w, curent : hwnd;
begin
  x:=FindWindow('WindowsForms10.Window.8.app3', nil);
  EnumChildWindows(x, @WinEnable, 0);
end;