Here's how you can use GNOME Classic instead of Unity in Ubuntu 12.04. 1. Open the Ubuntu Software Center. 2. Type in "gnome shell" without the quotes into the search box. 3. When you find GNOME Shell, click the Install button. 4. After the install is complete, logout out of Ubuntu 12.04. 5. Choose GNOME Classic from the login screen and you'll use that instead of Unity for your desktop environment in Ubuntu 12.04. Unity has gotten better, but some people still prefer GNOME Classic.
For more, see the original article at the link below.

How to return to classic Gnome in Ubuntu 12.04 Precise | IBM
