Please Help, I've just gotten a new PC and although I imported all files, folders & saves over to the new machine it didn't keep my progress in Rome II's Historical Battles. I tried Googling a solution but best I found was someone claiming that progress is saved on Registry Keys & I'd have to edit that. I was always told messing with Registry could brick your machine.
I actually cut & pasted the Entire 'Rome II' folder from my old Win7 PC into new Win 10 PC's %appdata% Creative Assembly folder. It gives me everything back (savegames, replays, settings etc) EXCEPT progress in the Historical Battles menu, stars and all. Check out the following link where the Napoleon Total War resolution was to mess with Registry Keys. https://forums.totalwar.com/discussion/54831/historical-battles-save-backup
Although I'm hoping for a safer way. Doing same for both Napoleon & Empire so hopefully similar locations for a file that does keep this kind of Non-Campaign Save progress.