A Lenovo G50 laptop with an AMD CPU and Radeon R5 GPU is the new laptop I bought to replace an old one.
Like virtually all OEM computers that ship with Windows 8, it has Secure Boot enabled. The real terminology is Restricted Boot, but we’ll leave that discussion for another post.
Leaving Restricted Boot enabled is fine if you intend to run just Windows 8, or the next version of Windows, only, or a Linux distribution that can tolerate Restricted Boot. However, if you intend to install a distribution like Linux Mint alongside Windows 8, you’ll have to disable Restricted Boot.
Linux Mint does not use digital signatures and does not register to be certified by Microsoft as being a “secure” OS. As such, it will not boot with SecureBoot. If your system is using secureBoot, turn it off.
So here’s how to turn off Restricted Boot on a Lenovo G50. The steps should be the same on other (Lenovo) computers, but perhaps with minor variations, if any. On a Lenovo G50, you access the InsydeH20 Setup Utility (BIOS/UEFI setup utility) by pressing the Fn+F2 key just as the system starts booting. You may also access it by pressing the Novo button on the left side of the unit, just beside the power connector, and selecting the appropriate option from the screen that opens.
Then scroll to the Security tab by using → . Then use ↓ to scroll to the Secure Boot entry. Press the Enter key and select Disabled. Follow that by navigating to the Reset to Setup Mode entry using the ↓ again. Press Enter, then select Yes on the popup to clear the PK, disable secure boot and enter setup mode. You’ll notice that the Platform Mode changes to Setup Mode and Secure Boot Mode becomes Custom. Press the Fn+F10 key to reboot.
When next you access the InsydeH20 Setup Utility > Security tab, you’ll see that the Secure Boot Status will be disabled. And if you ever wish to restore the settings, access the Security tab again, navigate to the Restore Factory Keys entry, and press Enter. Restricted Boot will be enabled on the reboot after that, provided you save the settings using the Fn+F10 keys.
Although not necessary for using or not using Restricted Boot, a setting you can also enable/disable, is UEFI/Legacy BIOS mode. I don’t see any reason to mess with this setting, but it’s under the Boot tab if you ever wish to change it.