If you can't remember the password in Windows 10 or you just want to start with a fresh installation, you can easily do this in the following way.
Make sure the PC module is on(You don't need to be logged in).
Make sure a keyboard is connected.
Now, on the keyboard, hold down the SHIFT key while choosing reboot (you can do this at the bottom right) after clicking the icon below:
Now click the 'Get started' button under the heading 'Reset this PC'.
Choose 'Delete everything'.
Depending on the version of Windows, you may be asked 'How do you want to reinstall Windows?', choose 'Download from the cloud' here.
Windows will now be reset.