Great to hear, it’s working now!
Multiprocessing is implemented a bit differently on Windows, e.g. it uses spawn instead on fork.
That means that you should guard your code with:
if __name__=='__main__':
    main()

You can read more about these differences in the Windows FAQ 3.
I’m not sure, how Jupyter notebooks should be handled on Windows machines, but I guess it might be related to the multiprocessing part.
Could you try to export your notebook as a Python script, add the guard, and try to run it again using more workers?