There are two courses of action that you can take. As others have said, flashing your firmware is an option, but it may not be enough. Flashing the firmware is writing to its flash memory, rather than the CMOS, which stores the actual user configurations/settings. A good option here would be to reset, rather than flash, your firmware. This is done by opening up the computer and removing your CMOS battery. (Also, a misconception: this is the UEFI, not the BIOS; those are two completely different things).
A little bit of background: the CMOS is a type of RAM that needs constant power to store its settings. If it loses power, then it loses its changes and resets back to its defaults, which are hardcoded into the CMOS itself. Removing the CMOS battery is basically resetting it to factory defaults, but it is more foolproof than resetting it from your UEFI, which you cannot do anyway.
The process may vary from computer to computer, and you may have to crack open your case with force on some newer laptops. Make sure you have a grounding wristband or at least ground yourself before opening up the case, because static electricity can damage your motherboard (grounding wristbands are super cheap, you can find one readily on Amazon for $5). When you find the UEFI chip(s), the CMOS battery is somewhere around; it is a circular, almost flat, silver cylinder. Take it out gently (making sure you are grounded before), and wait for 5 minutes before inserting it back in.
Some motherboards have fixed CMOS batteries, however. These motherboards will most likely have a CMOS jumper that can reset it. Around the CMOS battery, there should be a jumper named CLEAR CMOS, PASSWORD, or something similar. Set it to the "clear" position, then move it back to where it originally was. Not all motherboards have this, though, and if you can't remove the CMOS battery as well, then you're pretty much stuck and can't use this method.
Reference this for a detailed explanation and pictures.