Downloads page of official website for Python’s standard distribution (https://www.python.org/downloads) has installers for Python 3.x and 2.x versions. At the time of writing 32 bit and 64 bit msi installers for Python 3.6.2 and python 2.7.13 are available. Download appropriate installer.
Invoke the installer with administrator privileges and go through the installation wizard choosing recommended options. Perform installation for all users and add python executable to path system variable when prompted to.
Run python.exe from command prompt. A command window with python prompt of three gt (>>>) symbols will appear. That confirms successful installation of Python on windows OS.