Nothing seems to stop that console window. set_non_modal does not work.

And even the windows specific code does not work.

    win.end();
    Fl::add_timeout(2.0, Update_CB, (void*)&progress);
    win.set_non_modal();
    win.show();
    Fl::check();
    //Sleep(500);
    Show_Topmost(&win);

And

>>

//----------------------------------------------------------------------------
void Show_Topmost(Fl_Window* pWindow) {
    HWND hWnd = fl_xid(pWindow);
    ShowWindow(hWnd, SW_SHOWNORMAL);
    SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
}