If your system has frozen, you might find that you need to shut down Windows as quickly as possible. Although you can accomplish this task simply by pressing the power button on the computer, there’s a way for you to shut down the computer that's less harmful to the operating system. To do it:
1. Press [Ctrl][Alt][Delete] to display the Windows Security dialog box.
2. Hold down the [Ctrl] key and click the Shut Down button.
3. Click OK to confirm that you want to perform an emergency shutdown of the computer.
Be aware that when you perform an emergency shutdown, Windows doesn’t prompt you to save any open documents. To avoid losing your work, make sure that you save anything you’re currently working on (if possible) before performing an emergency shutdown.