I updated my Ubuntu and while it was restarting command line appeared and froze, then I forced shutdown PC and when Ubuntu booted again, I saw unity is corrupted. Launcher and menus disappeared but Alt+Ctrl+T and Righ-Click menu works. Also I can open Firefox and other apps through terminal. This is how my current desktop:
Reset Compiz configurations
dconf reset -f /org/compiz/
Try to completely remove your ATI drivers from your system:
sudo apt-get purge fglrx*
Remove your xorg.conf
sudo rm /etc/X11/xorg.conf
Reinstall xorg completely
sudo apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 libgl1-mesa-glx:amd64 libgl1-mesa-dri:amd64
Re-configure Xorg
sudo dpkg-reconfigure xserver-xorg
Reboot
sudo reboot
by Bruno Pereira
Now you should reconfigure Unity. It will remove Unity completely.
sudo apt-get install ppa-purge
sudo ppa-purge ppa:unity-team/staging
apt-get install unity
Install Unity again.
sudo apt-get update
sudo apt-get install --reinstall ubuntu-desktop
sudo apt-get install unity
sudo reboot
by Justinas Dūdėnas and mpm
It works for me just great.
For 12.04 and older:
unity --reset
run this command it will fix the problem,but not perfectly,running unity --reset will reset all of the launcher options, but it won't remove your custom favorites. To also remove any launchers you've added to the launcher, run
unity --reset-icons
Or manually by:
gsettings reset com.canonical.Unity.Launcher favorites
I would recommend running the gsettings command before unity --reset, so that you won't have to restart unity for the gsettings key reset to take effect.
http://www.addictivetips.com/ubuntu-linux-tips/how-to-reset-unity-to-default-settings-in-ubuntu/
