title: Using gym atari (version 0.9.5) in python on windows
body: <p>Im trying to install the gym atari package on version 0.9.5 (I specifically need this version), but when I run the code (which is supposed to be running smoothly if gym is properly downloaded), I get the following error:</p>
  <pre><code>AttributeError: 'AtariEnv' object has no attribute 'viewer'
  </code></pre>
  <p>The problem occurred when I tried to run <code>gym.make()</code>.</p>
  <p>Does anyone know how to fix this?</p>
  <hr />
  <p>The same behavior happened to me with python 3.9, but for some reason not on python 3.8 (there was a different error there). Maybe Im missing some rendering library?</p>
  <hr />
  <p>The full error message is:</p>
  <pre><code>[2021-05-22 02:17:05,405] Making new env: PongNoFrameskip-v4
  C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\registration.py:17: PkgResourcesDeprecationWarning: Parameters to load are deprecated.  Call .resolve and .require separately.
    result = entry_point.load(False)
  Traceback (most recent call last):
    File &quot;C:/Users/1/PycharmProjects/University Homework/Reinforcement Learning/dqn/main.py&quot;, line 61, in &lt;module&gt;
      env = get_env(task, seed)
    File &quot;C:\Users\1\PycharmProjects\University Homework\Reinforcement Learning\dqn\utils\gym.py&quot;, line 13, in get_env
      env = gym.make(env_id)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\registration.py&quot;, line 164, in make
      return registry.make(id)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\registration.py&quot;, line 122, in make
      env = spec.make()
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\registration.py&quot;, line 89, in make
      env = cls(**self._kwargs)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\atari\atari_env.py&quot;, line 32, in __init__
      self.game_path = atari_py.get_game_path(game)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\atari_py\games.py&quot;, line 20, in get_game_path
      raise Exception('ROM is missing for %s, see https://github.com/openai/atari-py#roms for instructions' % (game_name,))
  Exception: ROM is missing for pong, see https://github.com/openai/atari-py#roms for instructions
  Error in atexit._run_exitfuncs:
  Traceback (most recent call last):
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\utils\closer.py&quot;, line 67, in close
      closeable.close()
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\core.py&quot;, line 164, in close
      self.render(close=True)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\core.py&quot;, line 150, in render
      return self._render(mode=mode, close=close)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\atari\atari_env.py&quot;, line 109, in _render
      if self.viewer is not None:
  AttributeError: 'AtariEnv' object has no attribute 'viewer'
  Exception ignored in: &lt;function Env.__del__ at 0x00000203EE2174C8&gt;
  Traceback (most recent call last):
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\core.py&quot;, line 203, in __del__
      self.close()
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\core.py&quot;, line 164, in close
      self.render(close=True)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\core.py&quot;, line 150, in render
      return self._render(mode=mode, close=close)
    File &quot;C:\Users\1\PycharmProjects\University Homework\venv37\lib\site-packages\gym\envs\atari\atari_env.py&quot;, line 109, in _render
      if self.viewer is not None:
  AttributeError: 'AtariEnv' object has no attribute 'viewer'
  </code></pre>
  <p>Also, the relevant code:</p>
  <pre class="lang-py prettyprint-override"><code>if __name__ == '__main__':
      # Get Atari games.
      benchmark = gym.benchmark_spec('Atari40M')
      
      # Change the index to select a different game.
      task = benchmark.tasks[3]
      
      # Run training
      seed = 0 # Use a seed of zero (you may want to randomize the seed!)
      env = get_env(task, seed)
  </code></pre>
  <p>And <code>get_env</code> is:</p>
  <pre class="lang-py prettyprint-override"><code>def get_env(task, seed):
      env_id = task.env_id
  
      env = gym.make(env_id)
  
      set_global_seeds(seed)
      env.seed(seed)
  
      expt_dir = 'tmp/gym-results'
      env = wrappers.Monitor(env, expt_dir, force=True)
      env = wrap_deepmind(env)
  
      return env
  </code></pre>