Open the command line, to do this right click on the Desktop and select Create Launcher… In the Command text field type in gnome-terminal and in the Nametext field Terminal click **OK
**

A new shortcut called Terminal will appear, double click on it to Open a new Terminal window

Type the following command
killall gnome-panelCreate another Launcher as in step one type in the command text box gnome-panel give it a name, and then run the launcher and the Gnome Panel will be back.

NOTE: If the Panel disappears again when re-booting try to install gnome-panel
sudo apt-get install gnome-panel