Download Windows 8.1 Disc Image (ISO File) – Microsoft
If you need to install or reinstall Windows 8.1, you can use the tools on this page to create your own installation media using either a USB flash drive or a DVD.
Before you begin
Make sure you have:
An Internet connection (Internet service provider fees may apply).
Sufficient data storage available on a computer, USB or external drive for the download.
A blank USB or DVD (and DVD burner) with at least 4 GB of space if you want to create media. We recommend using a blank USB or blank DVD, because any content on it will be deleted.
Download Windows 8.1