How to reboot Lenovo thinkpad laptops to install windows 10 operating system?
Turn on the laptop then Press F1 key at the lenovo screen (you will hear a beep sound if your operation is successful), this will lead you into BIOS. Then go to the boot menu
The other member just needed to know how to boot into a dvd drive or flash drive so needed access to the bios so he could choose. He would have needed to have a copy of windows 10 on either a dvd drive or a flash drive.