At least 8GB of space. It will be formatted, so back up its data. Internet Connection: Needed to download the ISO file.
Once you have the ISO, you need to "burn" it to a USB drive so your computer can boot from it. Using Rufus (Recommended) Download and open . Select your USB drive under "Device." windows 8.1 clean install download
Restart the PC and immediately tap the (usually F12, F11, F10, or ESC). Select your USB drive from the list. Press any key when prompted to "Boot from USB." Step 4: The Windows 8.1 Installation Process At least 8GB of space