|Are you even sure a bios update is available for whatever machines you have?|
I assume you want the update in the hope you'll be able to use larger drives. As they are now, if the bios can see a 2 gig drive it'll probably see up to 8 gig. And the CLJ, as already mentioned, will make higher capacity drives usable.
Even if they don't have floppy drives, do the motherboards have a floppy port? If so you can temporarily connect a floppy drive to do the update, assuming an update is available.
Ding dong the witch is dead. . . .