desktop-save-mode

desktop-save-mode is a variable defined in `desktop.el'.
Its value is

nil

Documentation:
Non-nil if Desktop-Save mode is enabled.
See the command `desktop-save-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `desktop-save-mode'.

You can customize this variable.