how to save photos that are stored in System preferences/Desktop

Hi

They are not stored in the system preferences app - that app is finding them somewhere else on your system. See the screenshot below. That panel I've outlined in red is a list of locations where the preferences app is finding photos.

In your system preferences, what is highlighted in that panel, when you can see your photos?

(in my screenshot below, desktop is highlighted - so it is finding those images on my desktop).

For future reference there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community. Uninstall Norton according to the developer's instructions.  

Do you have a backup strategy enabled for you MBP, i.e. like Time Machine? If you do you can recover the Photos library by entering Time Machine, going back to just prior to running Norton and restoring the library.

If you don't then you should because it's like driving without a seat belt. You'll eventually need it.

Hi

They are in the photos app - that is what you have selected in the left hand pane.

Hold down the option key while starting the photos app. Select the library which is the system library to open from the list that comes up - the one that has "(system library)" after it, then click "choose library". (It looks like the top one in the screenshot). I expect your photos will come up in the app.

Glad you are sorted. Thanks for letting me know.