In Ubuntu 10.04, my network-manager icon is gone missing by itself. I use the GNOME desktop.
How can I restore it?
"If you remove the notification area on the panel (right click the three vertical dots and click "Remove From Panel") and then re-add it ( right click the panel, click "Add to Panel" and search for "Notification Area", then click it) the Network Manager icon will reappear, thus allowing you to connect to wireless networks."
Original answer from here