This article explains how to install Windows 8 or 8.1 using a USB device. It also includes a workaround for installing Windows 8 on a UEFI-based system.
How to Install Windows 8.1 from USB (Guide/Tutorial) (The Easiest Method)
If you want to install Windows 8 from a USB device, you need to copy the installation files from the DVD to the USB flash drive. Simply copying them there is not enough. Whether you have a Windows 8 DVD that you want to put on a flash drive or an ISO file for the same purpose, the following tutorial will help you copy the installation files to a flash drive.
It's a relatively simple process that takes 20 to 30 minutes, depending on the format of your copy of Windows 8 and the speed of your computer.
To complete this process, you will need the following: