I had setup compiz and advanced desktop effect sitting then i change the effects and enable cube.when I restart the computer all menus are disappeared.how can I fix this problem?
If you can get to the log in screen, you can hit Ctrl+Alt+F2 - this brings you to a terminal log in prompt. Log in with your username and password. Then type:
Hopefully this resets your interface properly, and you will have your menus back. Unfortunately, this will probably reset all your Compiz settings to default. However, you should have your interface back.