The bios access is before the computer gets that far....take the floppy out, restart the computer, and I think for Dells, it's the F 1 or F 2 key....keep tapping both repeatedly.....of course, one at a time, then you'll need to restart and try the other one.
Oops, on a quick check at Dell's site, it appears it's the F 2 or DEL key....
keep tapping one of those while the computer is starting up.