Hello, My Bios v.217 hast lost CSM/Legacy Options and SecureBoot. Current situation: UEFI boot only, secureboot enabled, win10 installed on gpt disk. Win10 works normally, but impossible to boot a MBR usbstick, and for personal reason I want to go back to Win7 with MBR scheme. I tried to flash older bios without succes (forbidden by FastFlash). I also disassembled to remove CMOS battery (5 minutes, not enough maybe), no progress. May be I should remove the CMOS battery for 2,3 or 4 days to reset the bios completely?? Is there any solution to recover those options (CMS, secureboot) ? Any help would be greatly appreciated