Flashcard profile settings and such are actually stored in the flashcard database, so those at least you're already backing up. There's no way to back up Pleco's regular Preferences-screen preferences, though, at least not without hacking around with a registry editor - we're hoping to add that ability in a future release, but it's a bit tricky since we need to store preferences in a way that'll do more self-correcting / be better able to migrate between different versions of Pleco than the way we store them now. (so it involves a significant redesign of the whole preferences system)