It would be of great help to users to know what kind of machine were talking here.
Laptop, desktop correct model or motherboard model, current bios, what error etc etc…
This is a forum and in a forum this details should be provided in this type of questions,
dont you agree? Humm ?!?!?
Lets try again and you can edit your post to add the relevant info…
EDIT: You can try the methods referred here on this guide, for non-USB Bios Flash Back models, AI Suite, AFUWIN, FlashRom, being as last resort the FPT method and CHA341A spi programmer, make backups of the current bios on the system as it will preserve SN UUID and MAC. The tool FD44editor also can read this data and save on text file this info, from a dump/backup.
Rollbacks can be as risky as flashing mods on some motherboards, be prepared for anything and its user choice only to proceed. Good luck