Enabling or disabling Secure Boot Prerequisite To enable this option: Set Boot Mode to UEFI Mode. Enable UEFI Optimized Boot. Procedure From the System Utilities screen, select System Configuration > BIOS/Platform Configuration (RBSU) > Server Security > Secure Boot Settings > Attempt Secure Boot. Select a setting. Enabled—Enables Secure Boot. Disabled—Disables Secure Boot. Save your changes. Reboot the server.