Change the Windows Vista Power Buttons to Shut Down
The default action for the Power button on the start menu in Windows Vista is Sleep, which isn't necessarily useful for everybody. You can configure this setting easily by using the advanced power settings panel.
(Control Panel \ Power Options \ Change Plan Settings \ Change Advanced Power Settings)
Once you get to this dialog, browse down as shown to "Power buttons and lid"
From here, you can change the options:
You can change the power button to either Sleep, Hibernate or Shut Down, or even nothing for the hardware power button.
taken from - http://www.howtogeek.com/howto/windows-vista/change-the-windows-vista-power-buttons-to-shut-down/
11-26-2007