Hi Alison and welcome to the forum:
The easiest thing to do is to go to the Canon support site for your camera where you can download programs that you can have free with your camera. These include a program called Digital Photo Professional - a free post-production software program that should retain your ratings and allow you to make adjustments and corrections to your files.
You will find all that at the following link: Canon Support for PowerShot SX70 HS | Canon U.S.A., Inc.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
