Disk Boot Failure, Insert System Disk and Press Enter

My 486 was working fine with Windows 95, Award Bios 4.05G, 2 Gb hard
disk, 1.44 floppy. A friend asked my to revive 5 1/4" floppies, found
a working 1.2 drive- after install, everything went wrong!
Booting up with a rescue disk or DOS 6.22 fails, getting first "Floppy
Disk(s) fail (40"), then F1 to continue, and get message, "Disk Boot
Failure, Insert System Disk and Press Enter". Pressing ENTER merely
repeats the message.
Have replaced cables, taken off the 1.2 floppy, the Ctrl-Alt-Del
restarts the computer in same sequence.
The BIOS finds the hard drive, the 1.44 drive operates...
Any ideas?
Thanks

The 5 1/4 drive is usually turned off in the BIOS. Change Drive B in
the BIOS to 5 1/4, and then makes sure that the floppy cable isn't
reversed.