ok, then there is no way to reset this online as you used an internal account, not an email address as the sign in.
In this situation you have to reinstall windows, there is no way to get around this. It will remove all your data and return the computer to new, but you cannot avoid this, it is the whole point of the security.
To do this, hold the SHIFT key on the keyboard and with it held down, click on the power icon on the screen then restart.
Keep shift held down until it has restarted and your at a menu.
Choose from this menu, Troubleshoot, then Reset My PC.
You will have to choose to remove all your files for this to work.
Let this complete and once it has, you will need to setup your computer again just like when you first received it.
Let me know please how you go.