I recently got a Thinkpad T440s with Windows 8.1 for my job, and since most of my work is done under Linux I am going to install Ubuntu on it, so that I can dual boot. The problem is that it won't boot from USB. In the BIOS, the Boot Priority Order only has the Windows Boot Manager and LAN, with USB devices appearing under "Excluded from boot priority order" lower down.
After preparing a USB flash drive as a Ubuntu installer, I thought I can get the computer to boot from USB at least once by going through the PC Settings window, then Update and Recovery -> Recovery -> Advanced Start Up -> Use a Device and picking one of the USB devices, but the computer just ignores the flash drive and boots straight into Windows.
On older computers I just use GRUB to pick what operating system to boot into, but with this computer I'm not sure how to best configure the start up - is Windows Boot Manager going to interfere?
I tried to search on Google but nothing I could find was really of help. The techs here won't help or support me, although installing Linux is allowed - and even necessary, in my case.