Set the Windows Vista Software Power Button Function
Windows Vista features a software Power button on its Start menu. It can be programmed to sleep, hibernate, or shut down when clicked. Assigning one of those functions to that button is possible, following these steps:
In the Control Panel window, choose Hardware and Sound.
Beneath the Power Options heading, click the link Change When the Computer Sleeps.
The link isn’t relevant to setting the software Power button function, but it gets you one step closer to the spot where that body is buried.
Click the link Change Advanced Power Settings.
The Power Options dialog box appears.
Click the plus sign (+) by the item titled Power Buttons and Lid.
Click the plus sign (+) next to the option Start Menu Power Button.
Choose an option for the Start menu Power button.
The options are Sleep, Hibernate, and Shut Down.
For battery-powered or UPS PCs, set both options: On Battery and Plugged In.
Click OK to dismiss the Power Options dialog box and confirm your choices.
Close the Edit Plan Settings window.
You can, though it isn’t easy, determine the software Power button’s function by observing the software Power button on the Start menu. An orange Power button means that either Sleep or Hibernation is chosen; a red Power button means that Shutdown is chosen.