If the machine lets one boot but does not want to let the user into the BIOS setup utility, because of the BIOS supervisor password one possible recovery is to deliberately "damage" the CMOS checksum by doing direct port writes using DOS command-line tool, corrupting some bytes of the checksum-protected area of the CMOS RAM; at the next boot, the CMOS typically resets its setting to factory defaults.Supervisor Password: This password prevents access to BIOS setup utility for preventing changing BIOS settings in the future.Create a new folder in which you will place the downloaded revisions.For this guide, I will be saving all necessary files to the following location:\SCS-CFGMGR-MP\SWSTORE\BIOSI have created separate folders for each model.In older computers with battery-backed RAM, removal of the battery and short circuiting the battery input terminals for a while did the job; in some more modern machines this move only resets the real-time clock (RTC).
Please note that this guide only applies to Dell systems.
Also, you can F10 to BIOS setup and actually there is an option to update the BIOS from USB drive…
To access the BIOS setup when the machine fails to operate, occasionally a drastic move is required.
The Debug command can be executed from booted Windows Command Prompt or from Free DOS . Install Free DOS on a USB flash drive using Rufus or UNetbootin. Download the tool and save it to the root of your USB flash drive. Boot up the computer with your USB flash drive and type the following commands: (take note that the second and third commands start with the letter O and not the number zero.) If the commands are similar to what cmospwd does to erase the cmos then this will brick a laptop that stores the password in an eeprom.
Updating the BIOS on multiple laptops and desktops can be a tiresome task that may just seem easier to do without.