To get the classic start menu, open the Terminal and enter the following command to install the Gnome Panel package:
sudo apt-get install gnome-panel
Once installed, log out, click the gear icon from the logon screen and select Gnome Classic before logging back in.
This will give you the Classic Start menu back in Ubuntu 11.10. If you login with the Classic Session, the Unity Launcher will not be available and all of the Classic Session options will appear as they did in earlier version of Ubuntu.
To find out what’s new in Ubuntu 11.10, check out our guide here.