08-07-2014 04:55 PM
I bought a ThinkPad 540p that comes with preloaded Windows 8.1. As I want to dual boot the machine I tried to select the Legacy Boot option in the BIOS/Startup tab, but I can't do anything as the option UEFI/Legacy Book is greyed out and locked in "UEFI Only". Below it there is an option called: -CSM Support that is also greyed out and selected as [No]. (below these options there is a little note with an asterisk saying "Unselectable for Secure Boot").
How can I enable the UEFI/Legacy Boot option again in order to dual boot the computer? I want to be able to boot from USB or from the CD Drive.
Thank you very much for helping me out!
Solved! Go to Solution.