Python was not found but can be installed from the Microsoft store (March, 2020)

Prior to do "start -> then search -> Manage App Execution Aliases -> turn off" make sure that you have added PYTHONPATH with details (C:\Program Files\Python37;) in system-environment-variable. Then do the "turn-off" as mentioned above. This will work

You don't have the command python installed into your PATH on Windows which is the default if you didn't get your copy of Python from the Windows Store. If you selected your Python interpreter in VS Code (look in the status bar), then I would disable Code Runner. That way the Python extension is what provides the ability to run Python (the Play button will be green instead of white).

python install directory, bin, and lib-scripts must be to the top of WindowsApps directory, like the image below