Apparently, there are cases where this win8-option is not even visible, until you fiddle with BIOS, usually. Links below report the problem for three laptops: Acer E1 571 (unsolved?), Asus N56VJ-DJ71 (mfg says turn off SecureBoot and enable CSM as a workaround), && Samsung Ativ 500T (worked well for most folks but at least one person did not see the menu-item at all -- workaround was to use F10 during boot to see boot-order-menu).
Re: 'use other devices' not always visible
Apparently, there are cases where this win8-option is not even visible, until you fiddle with BIOS, usually. Links below report the problem for three laptops: Acer E1 571 (unsolved?), Asus N56VJ-DJ71 (mfg says turn off SecureBoot and enable CSM as a workaround), && Samsung Ativ 500T (worked well for most folks but at least one person did not see the menu-item at all -- workaround was to use F10 during boot to see boot-order-menu).
http://superuser.com/questions/528636/missing-use-a-device-option-to-boot-a-live-distro-from-usb-on-a-windows-8-uef
http://forum.tabletpcreview.com/samsung/53946-boot-usb-500t-3-print.html