How to restore system default settings in ubuntu 16.04?

Question

I am trying to restore the unity control center but there are always missing items even after I run:

sudo apt install unity-control-center

and

sudo apt install ubuntu-desktop

And this is what I get:

You can see some items are missing, like Language support, Security & privacy, Additional drivers, Printing, Backups, Software updates

Solution

I recommend you to restore Ubuntu from live CD. Download the iso and reinstall Ubuntu. It is the fastest and best way to fix your problem. Othrewise you can run sudo apt install --reinstall ubuntu-desktop and sudo apt install unity. After these commands you might need to run unity on a terminal

Comments

[doug]

For starters ck & see if the activity-log-manager package is installed. If it's not then install it & the Security & Privacy panel should return. If that's the case then the rest of the missing can be returned by finding the missing packages.