If you were using PostgreSQL v12 before then after uninstalling it you will need to delete the 'data' folder that gets left behind before reinstalling it:
C:\Program Files\PostgreSQL\12\data\To reset PokerTracker 4 to default you can delete the following folder:
C:\Users\{Windows Login}\AppData\Local\PokerTracker 4although I'd recommend renaming the folders above rather than deleting them in case you need something from them later (for example your
original hand histories are archived in the folder listed above). If you do not see the AppData folder in Windows File Explorer then please refer to
this guide.