app.hookman.register('window1', 'after_open', progress_bar1)
    app.hookman.register('window1', 'after_open', progress_bar2)
    app.hookman.register('window1', 'after_open', update_scale)
    app.hookman.register('window1', 'after_open', refresh_scale)

    app.hookman.register('window2', 'after_open', create_process1)
    app.hookman.register('window2', 'after_open', create_process2)

    app.hookman.remove('window2', 'after_open', create_process1)