What should you do before flashing the BIOS?

Before flashing the BIOS, backing up the CMOS settings is essential because it preserves the configuration of the system's settings. BIOS settings can include vital information such as boot priorities, hardware configurations, and overclocking settings, all of which can be reset to factory defaults during the flashing process. If an issue arises during or after the update, restoring the CMOS settings can help revert back to the previous working configuration, reducing the chance of system instability or failure to boot.

The other options, while they may contribute to a smoother overall update process or system recovery, do not specifically address the immediate concerns associated with the BIOS update. Updating the operating system may ensure compatibility but does not protect BIOS settings. Creating a restore point is more relevant to the operating system level rather than the BIOS. Removing all peripherals, while it may prevent certain conflicts, does not safeguard critical BIOS settings that could be lost during a flash.