Yes, you'll need a Windows 8 license key to validate the install. Once the media creation tool is finished, you can use the USB flash drive or DVD (after rebooting) to install Window 8.1. Let it start to configure your PC and 'check for updates' while setting up. During setup get it on wifi (if your not hardwired) dont skip this step. Head to Microsoft's installation tool webpage, connect your USB flash drive (at least 4 GB of space should be available) or insert your writeable DVD, and then click the Create media button. Do you have 8.1 install media Or are you installing 8, then update to 8.1 then upgrade to 10 If your re-installing back to 8.1, this is what I did 1. Save the ISO image to a USB drive for emergency reformatting and installations (we've all been there before) or just peace of mind. The free tool downloads and creates the installation media you need to install Window 8.1 right away, without having to first install Windows 8 and then update to Windows 8.1, a lengthy process.
Media Creation Tool can be helpful to users who want to perform a clean install of Windows 8.1 or users who want to re-install the operating system but have lost the original installation media. It could come in handy if you ever want to reinstall Windows 8.1 or install it from scratch. Windows Installation Media Creation Tool can be used to download official Windows 8.1 ISO image files from Microsoft without entering the product key. Want to reinstall Windows 8.1 but don't have any installation media for it? Microsoft has released this new tool for you.