How to restore healthy Unity after incomplete update

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.