Saves the current file as the default Blender file
This file is loaded every time Blender is opened or a new file is generated ( ).
It contains the default startup scene included with Blender. This startup scene can be replaced by your own customized setup.
To change the startup scene, make all of the desired changes to the current scene or current file and.
startup.blend still stores user preferences in the file.
Only if a
userpref.blend exists, it uses the preferences from that file.
(ToDo add): Restore Load Factory Settings.