TOPIC:

I have my preferred configuration which means I make many changes in Tools,Options.  These often get lost, especially after upgrading.  What file(s) need to be saved so that all those changes can be restored without having to enter them all?  Or is there an option on the menu?

Every CT configuration area has save/load to xml file ability.
Before CT update or rebuild, save your critical areas configuration.
After CT update or rebuild, load from saved xml file, your critical areas configuration.