Just linked this in another comment, but I’ll post it here too: https://www.techdirt.com/articles/20150812/11395231925/lenovo-busted-stealthily-installing-crapw

Just linked this in another comment, but I’ll post it here too: https://www.techdirt.com/articles/20150812/11395231925/lenovo-busted-stealthily-installing-crapware-via-bios-fresh-windows-installs.shtml https://www.techdirt.com/articles/20150812/11395231925/lenov... Short version, manufacturers can use a feature called WPBT to load executables into your “clean” Windows installation from firmware. It’s intended for providing drivers.