Turn off a computer: frequently asked questions

By default, Windows puts your computer into an energy-saving mode called sleep when you use the power button on your computer. This applies both to the physical power button and to its software counterpart, which you can find by clicking the Start button .

The Power (sleep) button

Sleep automatically preserves your open documents and programs in memory and shuts down all nonessential functions. (A flashing or colored light on the computer case typically indicates your computer is sleeping.) The advantage of sleep is that it takes only seconds to restore your computer to where you left off—and uses only about as much electricity as a night light.

However, if you want to power down your computer completely, click the arrow next to the Lock button and then click Shut Down. This option closes any open programs (you'll have the opportunity to save your work), shuts down Windows, and powers down your computer.

If you prefer to always have Windows shut down instead of sleeping when you click the Power button (or its physical counterpart), you can change the button's default setting:

When you exit a program, it may not always exit "gracefully." For various reasons, software programs sometimes prevent Windows from shutting down properly. When that happens, the screen darkens and Windows indicates which programs are preventing the computer from shutting down. It may also indicate why those programs are preventing your computer from shutting down.

The darkened screen displays two buttons: Shut down now and Cancel. Clicking Shut down now forces all of the programs to exit and completes the process of shutting down your computer. However, if you click this button, you may lose any data that you haven't saved. If any of the programs that are preventing shutdown have data that you want to save, click Cancel to return to Windows and save your work.

Occasionally you may have to shut down a non-responsive software program manually. To learn more, see Exit a program that is not responding.

The Lock button prevents other people from accessing your computer or viewing your work. It's an ideal way to protect your computer when you need to step away to the bathroom or to lunch. It's also much quicker to lock and unlock your computer for short periods than to shut it down or put it into a power-saving mode such as sleep.

To lock your computer, click the Start button , and then click the Lock button .

Once locked, Windows will display the Welcome screen.

The Welcome screen

To unlock your computer and resume working, enter your password. For more information about creating a password, see Protect your computer with a password.

Sleep is a power-saving state. Sleep saves all open documents and programs, and allows the computer to quickly resume full-power operation (typically within several seconds) when you want to start working again. Putting your computer to sleep is like pausing a DVD player: the computer immediately stops what it’s doing and is ready to start again when you want to resume working.

To put your computer to sleep, click the Power button on the Start menu or click the arrow next to the Lock button .

The Sleep option is located on the Lock menu

You can typically put a mobile PC to sleep by closing its lid. Some computers also have a physical sleep button on their cases, often located near the power switch.

Depending on your computer's power management settings, you computer may also automatically go to sleep after a period of inactivity to conserve energy. To adjust these settings, see Change, create, or delete a power plan (scheme).

While your computer is asleep, its hardware lights may slowly flash or change color. This is normal.

On most computers, you can resume working by pressing the power button. However, not all computers are the same. You may be able to wake your computer by pressing keys on the keyboard, clicking your mouse button, or opening the lid on a mobile PC. Check the documentation that came with your computer, or go to the manufacturer's website.

If it's just a few hours or even overnight, it's usually more efficient to put your computer to sleep, either by clicking the Power button on the Start menu or by closing the lid on your mobile PC. (Some computers also have a dedicated sleep button on the computer case.)

There are several advantages to choosing sleep over shutting down:

• All your work, including information about the programs you were using such as window location and size, is automatically saved.

• When you awaken your machine from sleep, you don't need to restart programs or reopen files as you would if you had shut down the computer.

• While Windows does use some power in sleep mode, it's very small: about one-tenth as much as it would need if you left the computer running. A mobile PC typically uses 1 to 2 percent of battery power per hour in sleep mode.

• When Windows is asleep, it can still download and install updates and perform other routine maintenance tasks. For this reason, some companies require employees to put their computers to sleep rather than shut them down when going home for the evening.

But there are instances when you should shut down your computer fully—for example, when you install a new memory card or other hardware. If you don't plan to use your computer for several days or more, you should also shut it down.

Yes. While your computer sleeps, Windows saves all open documents and programs to memory. As long as your computer doesn't suddenly lose power, your work is safe.

If your mobile PC's battery charge grows critically low while the computer is asleep, Windows will automatically save your open documents and programs to your hard disk and turn off the computer. This is a power-saving state known as hibernation. When you turn on your computer again, Windows takes a little longer to resume, but all of your work will be saved.

To protect desktop computers from data loss, Windows has a new feature called hybrid sleep. When you put your computer to sleep, hybrid sleep automatically saves your programs and open documents both to memory and to hard disk. If a sudden power failure occurs, Windows can restore your work from disk.

When hybrid sleep is turned on, clicking Sleep on the Start menu automatically puts your computer into hybrid sleep. When hybrid sleep is turned off, or if your computer doesn't support hybrid sleep, clicking Sleep puts the computer to sleep.

Tip

• When your computer wakes, you can prevent unauthorized access by requiring a password to unlock it. For more information, see How do I change the password requirement when my computer wakes from sleep?

Like sleep, hibernation is a power-saving state. But while sleep typically saves your settings in memory and draws a small amount of power, hibernation saves your open documents and programs to your hard disk and then turns off your computer. Of all the power-saving states in Windows, hibernation uses the least amount of power.

To put your computer into hibernation, click the Start button , click the small arrow next to the Lock button , and then click Hibernate.

Windows automatically puts a mobile PC into hibernation mode when the computer's battery grows critically low.

On a mobile PC, use hibernation when you know that you won’t use your mobile PC for an extended period and won't have an opportunity to charge the battery during that time.

On most computers, you can resume working by pressing the power button. However, not all computers are the same. You may be able to wake your computer by pressing any key on the keyboard, clicking a mouse button, or opening the lid on a mobile PC. Check the documentation that came with your computer, or go to the manufacturer's website.

Hybrid sleep is another new power-saving feature designed primarily for desktop computers. Hybrid sleep saves any open documents and programs to memory and to your hard disk, and then puts your computer into a low-power state.

Unlike mobile PCs, desktop computers typically don't have battery-based power backup. So if a sudden power failure occurs to a desktop computer in standard sleep mode, data loss could occur.

But with hybrid sleep turned on, Windows can restore your work from your hard disk. On desktop computers, hybrid sleep is typically turned on by default.

When hybrid sleep is turned on, clicking Sleep automatically puts your computer into hybrid sleep. When hybrid sleep is turned off, or if your computer doesn't support hybrid sleep, clicking Sleep puts the computer to sleep.

To turn hybrid sleep on or off:

Sleep saves any open documents and programs to memory, and then puts your computer into a low-power state. Hybrid sleep saves any open documents and programs to memory and to your hard disk, and then puts your computer into a low-power state.

An advantage of hybrid sleep is that if a power failure occurs, Windows can restore your work from your hard disk. If a power outage occurs when your work is saved only to memory, your work is lost.

On most computers, you can resume working by pressing the power button. However, not all computers are the same. You may be able to wake your computer by pressing any key on the keyboard, clicking a mouse button, or opening the lid on a mobile PC. Check the documentation that came with your computer, or go to the manufacturer's website.

No. Sleep requires an extremely small amount of power—about the same as a nightlight. If the battery on your mobile PC eventually becomes critically low, Windows saves any open documents and programs to your hard disk, including information about the programs that you were using, and then shuts down your computer to prevent the battery from draining completely.

You can adjust how long your computer will wait before sleeping or hibernating—or prevent it from turning itself off altogether. But be careful: On a battery-powered mobile PC, inhibiting sleep or hibernation can result in data loss if the battery goes dead. Here's how to prevent your computer from entering a power-saving mode:

The Restart and Shut Down options are now available on the Lock button menu. To see the option, click the Start button , and then click the arrow next to the Lock button .

The Lock button menu offers several options for shutting down

On this menu, you can also log off, lock your computer, restart your computer, or switch users without logging off by using Fast User Switching.

By default, Windows puts your computer to sleep when you click the Power button. However, you can change the default setting so that clicking the button causes your computer to sleep, hibernate, or shut down. (Any changes you make will also apply to the physical power button on the computer itself.) To change the default setting:

If you can't find sleep, your computer may not support it. For more information, see Why isn't Sleep available?

If the hibernate option is missing, your system administrator may have turned it off, or you may have hybrid sleep turned on.