If you are careful and avoid using cutting edge repositories, then the following commands may not be really important to you. However, if like me you always have to try and tweak that one last thing, the day that you fail to have a desktop materialize on your screen, these commands will help you get things reset and hopefully you will be back up and running in no time. To access a terminal use the Ctrl-Alt-Fn(#) keys shortcut where # is 1-6. You can log in with your standard account and follow the instructions below.
If you don’t have dconf-tools installed, issue this command (otherwise proceed to the next command):
sudo apt-get install dconf-tools
To reset Unity desktop use the following command:
If Compiz appears to be the problem, Compiz can be reset with the following:
dconf reset -f /org/compiz/
Please understand, these commands will reset everything back to the day you installed.
Disclaimer: I take no responsibility for any issues that may occur as a result of any of these commands. These commands have worked successfully for me in the past and should work fine in most cases.