The Home Small Business 5959 auto update worked. I had one system I had to search and copy svchost.exe to the windows/system32 folder. My recovery method was to rename the DAT folder to /broke. When I did that, I was able to boot normally, double click on the mcafee icon and check for an update.
I am greatly relieved that I did not have a hardware problem like I originally thought, nor a virus infection, which I next feared, or that I did not format and reinstall windows, or go off and buy a new PC, or any of the other possible solutions I was contemplating. This was the most benign outcome possible, other than mcafee not failing in the first place and me not loosing an entire day. I have 300+ days until renewal. I wonder what I will do then.