I messed up with the Compiz configuration. I was supposed to disable Compiz and so I unchecked every option. But as a result, I lost desktop side bar launcher, the top desktop menu bar, and everything except for the mouse pointer. I restarted the computer using the power button but my desktop still came back just showing only the wallpaper and mouse pointer.
The Google advice that helped me were:
Ctrl-Alt-T //This is to open the terminal window.
$ dconf reset -f /org/compiz/
$ setsid unity
The above reset my Unity and Compiz. Instantly, my desktop returned to normal.
Additional, but I did not do this anymore because the former is enough then.
-> Install dconf tools, $ apt-get install dconf-tools.
