Microsoft offers a special tool for creating installation media for Windows 8.1.
Using this tool you can create an bootable USB drive or DVD for installing Windows 8.1.
Further information and the download links for the Media Creation Tool can be found at the following link:
http://www.microsoft.com/en-gb/software-download/windows8
All further steps are explained in the process itself. If you have any problems activating your purchased activation please contact us at [email protected].