The BIOS update worked without a hitch!
The readme.txt says not to format the floppy in Windows NT, 2000, or XP. So I formatted the floppy in Windows 98SE and followed the remainder of the instructions with no issues.
A pleasant but unexpected side effect, is that my computer boots significantly faster now!
Unfortunately it was not the solution to my processor upgrade issues, however. It turns out that the processor was not compatible with my motherboard to begin with. Back to EBay!
Thanks again for your help, Sylvia.