When you buy a new Windows computer, the install software for the OS is usually placed on the hard drive inside a separate partition. If you upgraded from Win 8 to 8.1, accessing this install will roll back your computer to Windows 8. From there, you would have to go through the pain of upgrading all over again. Windows 8.1 does include tools to reset the OS to its default settings, or reinstall it. But what if something goes so wrong with Windows 8.1 that you can’t even start it? As a hedge against such a catastrophe, this guide will show you how to backup your Windows 8.1 setup, and how to use it to restore the OS.