Oh, just type %AppData% like I showed in the picture and press enter! You will be automatically directed to your AppData folder & you just need to find folder RenPy >>> Bermuda! ^.^)/
Edit: If you can see the CG images & already replaced the persistent file in AppData, but still encounter the same problem. Then you've done things correctly but for some reason, RenPy is reading your data as 'never seen' this scene in Day 17. Perhaps because there's something involving Guntur there?
If you click new game and can skip the Prologue, then you've done things correctly! It's just that Ren'Py doesn't skip Day 17 for some reason, try go forward and see when the Skip button lights up again