The genesis of my problem was when my computer became useless last autumn. Win10 ran a troubleshooter and advised me to do their wipe and reload. That gets rid of all applications but leaves the data files.
The problem started when TQSL stopped working. Apparently, TQSL won't reload certificates onto a "different" computer. Since it has a new OS build, to TQSL, this is a "different" computer. I got only the certificate for my latest call and QTH. When I was trying to fix my requested QSO's in LoTW, when I updated and uploaded to LoTW, it caused everything to be overwritten as W1ES and QTH as Graham.
I have asked Bart at LoTW to send me new certificates.
When I get the new certificates, am I correct in thinking that I will have to make the mass change per the instructions, then upload to LoTW again?
Sorry this has been such a mess. There are so many interactive pieces here.