Just got a new computer
Transfered Calibre folder full of my books from old pc to Documents, and have been backing it up and adding more books to it for a couple of weeks.
It says I have 1042 folders in that folder.
Just found out I also have a calibre folder in c drive!
That has 900 book folders in it.
The only reason I noticed was because some of my recent downloads were not in the Documents Calibre.