Answer
In most cases, ArcGIS and Python install and work together correctly, however, there are certain special case scenarios that may cause problems. Each of these scenarios is based around the logic ArcGIS uses to check the system for the existence of Python. Future versions of Python can be installed, provided the appropriate version of the PythonWin application is also installed. A complete document addressing possible issues that may occur and the relevant solutions can be downloaded from the link in the Related Information section below. The file is zipped and must be saved to the machine and unzipped before being opened.