;-) If you can boot from floppy without reaching the password prompt, then it’s (probably) just a software thing added to the startup sequence. You could remove it from the startup sequence by booting from floppy, then using an editor to edit the file DH0:s/startup-sequence (assuming the hard drive’s device name is the usual DH0: Failing that, just use the hard drive’s volume name, which would be given under the hard drive’s icon.)
:-) The card sounds like a hard drive controller. If it uses a forty pin connector, it’s an IDE, if it uses a fifty pin connector, it’s SCSI. Empty chip sockets are not uncommon on add-in cards; they’re to allow for future expansions that may never have been produced.
;-) In your position, I think I’d just boot from floppy, reformat the hard drive, and then install Workbench from scratch.
:-( Of course, I might regret it right away….