I use to store the Registration file for my program in the Application Support Folder and User Prefs in their Home folder on Mac and Windows (10 years back?).
Somewhere a long the way that system broken down and I received complaints from customers that It requested that they enter the registration number every time they ran the program. So I am assuming the OSs changed along they way and I think that use to work for network installations as well.
Before I jump in I was wondering are there preferred ways listers are using.