I know this is a question I should know the answer too, but wanted to make sure I understand it correctly. If you install ArcGIS Desktop and do not include Python in the installation, how do you install Python after the fact?
I need to explain how to install Python with ArcGIS Desktop if it was not installed during the initial install.
Get your media (install data folder) available, and run the setup again with new options, it will just overwrite your current install, no harm, no foul.
Another approach is to go to Windows Add/Remove Programs, find ArcGIS Desktop in the list and right click / Repair.
