"C:\Developing\Python" is where I installed Python, selecting it in the installer. This directory is where the binary 'python.exe' is located!
"C:\Developing\Python\Lib" have the folders:

idlelib
site-packages
test
tkinter
turtledemo

When I unset both variables, the same error occurs:

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Python path configuration:
  PYTHONHOME = (not set)
  PYTHONPATH = (not set)
  program name = 'python'
  isolated = 0
  environment = 1
  user site = 1
  import site = 1
  sys._base_executable = 'C:\\Developing\\Python\\python.exe'
  sys.base_prefix = ''
  sys.base_exec_prefix = ''
  sys.executable = 'C:\\Developing\\Python\\python.exe'
  sys.prefix = ''
  sys.exec_prefix = ''
  sys.path = [
    'C:\\Developing\\Python\\python38.zip',
    'C:\\Developing\\Python\\python-3.8.0.amd64\\Lib\\',
    'C:\\Developing\\Python\\python-3.8.0.amd64\\Lib\\lib-tk',
    'C:\\Developing\\Python\\python-3.8.0.amd64\\DLLs\\',
    'C:\\Developing\\Python',
  ]
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
ModuleNotFoundError: No module named 'encodings'

Current thread 0x000060e8 (most recent call first):
<no Python frame>
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