If you want to get an older version of Python release, Just scroll down a bit to the main download page of python/downloads
Double-click on the icon of the downloaded file labelled as (choose 32 bit/64bit)
An Open File – Security Warning pop-up window will show.
Click on RUN and a Python 3.x.2 (32/64-bit) Setup window will pop-up.
A User Account Control window will appear, questioning the user if he wants to allow the program to make changes to his computer.
During installation, the various components getting installed will be shown and the progress bar will continue to move towards completion. Then, a new Python 3.6.2 (32-bit) Setup window will pop up showing success message.