Software & Updates "Settings" button missing

Solution 1:

I found the answer: sudo apt-get install ubuntu-desktop This gave me the following:

The following NEW packages will be installed: apturl apturl-common nautilus-share software-properties-gtk ubuntu-desktop

I have no idea how these got deleted, but they're back now.

if setting is missing first check for gnome by

$ gnome-control-center

if it shows

bash: gnome-control-center: command not found

then run command:

$ sudo apt-get install gnome-control-center

for "software and updates setting" missing run command:

$ sudo apt-get install ubuntu-desktop

you are Done.