Thank's again for your quick answer.
I appologize but when I downloaded the 7 files, based on their naming I was guessing it's a "multivolume rar archive" splitted accross 7 files (as I usually deal with about film/series/book/... download sites).
So I extracted each "single rar archive" and used FFSJ and... it's ok now
Will deal with the activator now !