A window in ubuntu always has the close/maximize/minimize buttons on the right top.If you’d like to have them on the left,here’s an easy way in this tutorial.
First,press ALT+F2 key combination and type gconf-editor to launch the Gnome Configuration Editor.


Navigate to apps–>metacity–>general,on the right find out the option called button_layout


Double click on it and change it’s value to close,maximize,minimize:menu.If you’re careful,you’ll find the two screens above have these buttons on the left and menu on the right.