Windows 10 factory reset

Download a Windows 10 image either officially using the tool (Recommended, https://www.microsoft.com/en-gb/software.../windows10) or an image directly (unofficially) from 3rd party websites (I cannot vouch for this site https://official-kmspico.com/windows-10-iso-download/).

Next fire up a tool like Rufus (https://rufus.ie/) then write the image to your USB.

Throw it into the device and boot from said USB and then follow your installer (you will lose all the data on the installation drive).