1.Press Alt+F2 to bring up the Run Application dialog box, enter “gconf-editor” in the text field, and click on Run.
2.The Configuration Editor should pop up. The key that we want to edit is in apps/metacity/general. So we double click each folder, until we reach the destination folder named general. On the right side of the windows we have listed something called "button_layout". Double click on the name and on the window that pops-up we enter the following:
and then we hit OK. The buttons should be back on the right side.