I recently had an unusual situation with a relative’s computer. All the USB ports were disabled and the keyboard and mouse did not work. It booted to the splash screen and I could not get any further. It was because of Windows Update KB4074588. I tried to boot from a live Linux Mint USB drive to save all her personal files but it would not show in the boot menu. I later found out it was because of fast boot or secure boot. The flash drive was made for UEFI mode. I got around it by creating a live Windows 10 USB drive. The keyboard and mouse did work with the live Windows 10. I also used it to uninstall the update. This is what brought me to my question. Is it possible to just plug in a live Linux flash drive and have it boot when in UEFI mode? With no keyboard or mouse it was not possible to turn off fast boot. Does fast boot and secure boot always have to be disabled?