Windows 8.1

Windows 8.1 is an upgraded operating system software for Windows 8 with improved visual graphical user interfaces from Microsoft.com.

The logos of Windows 8/8.1 from microsoft.com:

The link of Windows 8.1 website is
http://www.microsoft.com .

The downloads of Windows 8.1 is
https://www.microsoft.com/en-hk/software-download/windows8ISO  last updated 22Aug2016

The related programs can be found at page
https://www.microsoftstore.com/store/msusa/en_US/cat/Windows/categoryID.62684800 last updated 10Feb2017

source: https://www.microsoftstore.com/store/msusa/en_US/cat/Windows/categoryID.62684800  last updated 10Feb2017