if one overwrites a file, will the previous version be moved to the system bin or just evaporate?
Last option.
Ah, :doh: !
Then one could further rename the second, (new) "trial" profile too - after the "bad" file's found, restart the browser to create a third, clean again, one, and copy-overwrite the renewed good file from there, after which delete it from there, or re-rename the last two folders back and proceed.
Alternatively, one could, straight after the browser creates a new profile, the first time that is, back that profile up, or files in it. Or just sraight away rename it somehow too and make the browser create a third one - with which to work.
Then we shall, too, have these three profile folders: one "old", renamed to copy-check the files, one a back-up clean, renamed too - to regain the "bad guys" after the work is nearly done, and a third, another clean - not renamed -- the one to receive in order to retain it as the new actual profile after the work's done.
The first two get then eliminated generally.
Yes, looks complicated, but if we don't know where the dog's buried and the issue is major...
