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.
08-07-2014 07:00 PM
Hello and welcome,
I'm not sure where it is in your BIOS (security tab maybe) but there should be an option to turn off secure boot.
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08-07-2014 07:46 PM
You are an absolute wizard!
I followed your advice and in the Security tab I went to Secure Boot option at the bottom, Selected Disabled for the Secure Boot and that did the trick for me, then on the Startup tab the UEFI/Legacy Boot was enabled again.
Thank you very much for your help, that's really appreciated!
07-26-2018 08:59 AM
Hi. I am not a computer pro but I just did this today. You have to change the secure boot to unsecured and then those options will appear. Hope this helps