[DiapDealer]

You can exclude folders from Windows Controlled folder access (or at the very least, turn it off entirely). I think that's what BR was saying. His calibre library is either located somewhere not under the control of the built-in controlled folder access, or he's disabled it.

EDIT: it seems you either turn the protection off, or you exclude applications from it. I always turn it off, since I don't install software with questionable pedigrees.