AutoCAD Civil 3D Filedia Command Video
This AutoCAD Civil 3D for Land Surveyors Video shows you how to use the FILEDIA command. I believe this command works for all flavors of AutoCAD.
The FILEDIA command controls the file dialog boxes, turning them either on or off, like those used when opening and saving drawings. Sometimes, when the program crashes, this command gets reset to "0" from "1".
Watch the AutoCAD Civil 3D Filedia Command Video