Hey again @Cellule_Boukham 
,
Streamlit does work at the Windows command prompt, but you need to make sure your Python environment is set up properly (which is actually not trivial on Windows!), and that Streamlit was installed in the right environment.
For this reason, on Windows we recommend using Anaconda Navigator. With it you first create a Python environment using an awesome graphical interface, and then launch a command prompt that is all set up with that environment by just choosing the “open terminal” menu option:
Inside that prompt you can do things like pip install --upgrade streamlit and streamlit hello, and they should just work!
Somewhat related, we just pushed a new release yesterday 0.49.0 that fixes several different Windows issues, so if you haven’t already, please upgrade and see if that helps with any issues you might be having:
$ pip install --upgrade streamlit
Note: There are still some open Windows issues, so please let us know if upgrading doesn’t fix it. Some of the other issues are tracked here:
Hope this helps and thanks for reaching out!