I think I have resolved the issue with the following steps: First need to install vs code then the "Desktop development with C++" workload I then was able to install g++ with "conda install -c conda-forge cxx-compiler" This then rectified the failed building wheel error and I was able to install nes-py with "pip install nes-py" Then I could install gym-super-mario bros with "pip install gym-super-mario-bros". I think you can just straight install gym-super-mario-bros without separately installing nes-py, but that is how I did it.