Bios Flashing

What is bios flashing and how can it be done?
Lost my bios settings due to battery failure.
I have replaced battery. I do not have a clue
of previous settings tried default and haphazzard
settings to no avail. I have been to bootdisk.com
already.I am not on a network.pc will not boot to
Dos prompt so I can reformat it and start clean
thank you…