Thanks, on PC, but what about the save? Do I need to start over?
Nope!
Saves transfer. They are located in game folder, but they are also saved in appdata folder, which isnt affected at all by you deleting the normal game folder.
You only need to start over with a New game if you used Walkthrough mod previously as it's no longer supported. Or if I make an announcement that starting over is required ^^