Hi Mate,
What kind of historical data do you think?
All characteristic - type:
"Favorites"
"route"
POI
poi_visiblities
etc. are iGO saved - so you can copy them and store, and later re-write it. - So you specify for it.

iGO has a hierarchical structure - so the change of sensitive data - such paths to directories should be preceded by cleaning the saved settings - the easiest way to do this by deleting the folder SAVE.
However, if you know - where and what - you can remove the settings of the program itself - without moving the navigation data (routes, waypoints, addresses).