You've never ran across Dell's proprietary BIOS that looks for a certain partition in the HD? For example, of you don't use Dell's recovery disk, wipe out the HD and treat the system as a PC clone system with a fresh OS install, you haven't seen the DELL prompt?
Run across Dell's propritary bios all the time, not getting away from that, but can't recall it looking for a certain partition. ( I reloaded 5 systems just last week )
The only time I can think of that I saw the "push F1 to continue " prompt is when a secondary hard drive had been removed. That's simple , disable the port.