readme clarification

README.md

@@ -55,7 +55,7 @@ as model if it has .pth extension. Grab models from the [Model Database](https:/
 
 ### Automatic installation/launch
 
-- install [Python 3.10.6](https://www.python.org/downloads/windows/)
+- install [Python 3.10.6](https://www.python.org/downloads/windows/) and check "Add Python to PATH" during installation. You must install this exact version.
 - install [git](https://git-scm.com/download/win)
 - install [CUDA 11.3](https://developer.nvidia.com/cuda-11.3.0-download-archive?target_os=Windows&target_arch=x86_64)
 - place `model.ckpt` into webui directory, next to `webui.bat`.