1) ctrl+alt+backspace注銷切換到登錄界面

2)左下角option里選擇change section, 選擇failsafe terminal

3)輸入帳號密碼進入后，在命令行輸入gconf-editor

4)依次選擇Desktop->Gnome->Applications->window_manager , 把兩處/usr/bin/compiz改成/usr/bin/metacity

5)ctrl+alt+backspace注銷切換到登錄界面，change section 選擇gnome

Good luck!