I am using Ubuntu Kylin 14.04.
Unfortunately I changed in the appearance settings program the window decoration/theme to "Ambiance" but the Kylin default one does not show in the list. How do I restore the Ubuntu Kylin default window decoration?
Open a terminal by ctrl-alt-t, and then type the following commands:
gsettings set org.gnome.desktop.interface gtk-theme ubuntukylin-theme
gsettings set org.gnome.desktop.interface gtk-theme ubuntukylin-icon-theme