Guys I have one doubt and I need your help. If we select Legacy option instead of new UEFI in BIOS settings and disable Secure boot option and then install Windows 10 on our computer, does it make any difference in performance and functionality of Windows 10 OS? Actually I have a Dell AIO PC and I disabled UEFI and Secure Boot options in BIOS settings and enabled Legacy option because it was not allowing me to select boot device options using F12 key at startup. When I enabled Legacy option, it allowed me to use boot devices. So after enabling Legacy option instead of UEFI, I installed Windows 10. Now I'm worried if I selected UEFI and Secure Boot option, would it provide any improvement in performance? Thanks in advance for replies.