No registered env with id: BanditTenArmedGaussian-v0 for the package gym_bandits of OpenAI I've made the following instruction : 

git clone https://github.com/JKCooper2/gym-bandits.git
cd gym-bandits
pip install -e .


After installing : 

import gym_bandits
import gym


Now we finally : 

env = gym.make("BanditTenArmedGaussian-v0")


Even tough the first three steps was successfull, the last one doesn't work. Here is my error :

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
c:\windows\system32\gym\gym\envs\registration.py in spec(self, path)
    120         try:
--&gt; 121             return self.env_specs[id]
    122         except KeyError:

KeyError: 'BanditTenArmedGaussian-v0'

During handling of the above exception, another exception occurred:

UnregisteredEnv                           Traceback (most recent call last)
&lt;ipython-input-13-645d2b1dfa73&gt; in &lt;module&gt;
      4 import math
      5 import random
----&gt; 6 env = gym.make("BanditTenArmedGaussian-v0")

c:\windows\system32\gym\gym\envs\registration.py in make(id, **kwargs)
    143 
    144 def make(id, **kwargs):
--&gt; 145     return registry.make(id, **kwargs)
    146 
    147 def spec(id):

c:\windows\system32\gym\gym\envs\registration.py in make(self, path, **kwargs)
     87         else:
     88             logger.info('Making new env: %s', path)
---&gt; 89         spec = self.spec(path)
     90         env = spec.make(**kwargs)
     91         # We used to have people override _reset/_step rather than

c:\windows\system32\gym\gym\envs\registration.py in spec(self, path)
    129                 raise error.DeprecatedEnv('Env {} not found (valid versions include {})'.format(id, matching_envs))
    130             else:
--&gt; 131                 raise error.UnregisteredEnv('No registered env with id: {}'.format(id))
    132 
    133     def register(self, id, **kwargs):

UnregisteredEnv: No registered env with id: BanditTenArmedGaussian-v0


Does anyone know how to fix it ? 

Thanks and regards.
The standard installation of OpenAI environments does not support Windows. See the GitHub issue here.

To get that code to run, you'll have to switch another operating system (i.e., Linux or Mac) or use a non-standard installation.