This guide will help you understand the process of installing windows 10 correctly.
Make a bootable drive
The first thing to do is getting the latest windows 10 files. Go here and download the link that says "Create Windows 10 installation media".
After that get yourself a USB or DVD and format it, then open what you downloaded:
and follow the steps to create the bootable windows 10 partition. It will download the latest files so it might take a while.
By the way ... now you can't create local accounts during installation.