I have an old small CF card for my "master" settings files.
I also keep a copy of the settings file on the card(s) I use for images. Before formatting I load the settings from the card into the camera; this overwrites any temporary changes I may have made during the previous shooting sessions. After formatting the card I immediately save the settings.
This strategy gives me 2 levels of backup and always allows me to get back to my "master" settings.
Gary in SE Michigan, USA. Nikonians membership - My most important photographic investment, after the camera. D4, D810, D300 (720nm IR conversion), D90, F6, FM3a (black), FM2n (chrome) YashicaMat 124, Graflex Speed Graphic 4x5 My Nikonians Gallery & Our Chapter Gallery