USB floppy and flash the BIOS - no OS necessary AFAIK
Why did you start swapping drives in and out in the first place?
The drive that was there would not boot. I ran a test - showed bad
sectors, fixed the bad sectors, still would not boot. Ran Dell diagnostics
and it said code 7 (usually a bad drive). The drive did show in my
main computer and I could use it for storage. I figured maybe the mbr
was bad with bad sector. Bought a new drive, formatted it and then
tried to boot it in dell. Once again, in the OS install procedure, I get
the
message that the system
cannot find a hard drive even though it does show in the bios setup.