The basic power button and what happens when you press it
To turn a computer on, locate the power button — usually a circle or rectangle on the front or side of the tower, or on the keyboard of a laptop. Press it once and hold for one second, then release. The computer will take 30 seconds to two minutes to fully start, depending on the model and how much is installed on it.
When you press the power button to turn the computer off, you have two choices: a soft shutdown or a hard shutdown. A soft shutdown closes all your programs and saves system files properly. A hard shutdown cuts the power when ready and can damage files or the hard drive.
Key Takeaways
- Press the power button once and release to turn the computer on; wait one to two minutes for it to fully start.
- To shut down safely, use the operating system menu (Start menu on Windows, Apple menu on Mac) rather than holding the power button.
- A soft shutdown through the operating system closes programs and saves files; a hard shutdown by holding the power button can corrupt data.
- If the computer freezes and will not respond, hold the power button for 10 seconds to force it off, then wait 30 seconds before turning it back on.
- Laptops may have a sleep mode separate from shutdown; check your settings to understand what each button does on your model.
How to shut down a Windows computer properly
Click the Start button in the lower left corner of the screen. A menu will open. Look for "Shut down" or "Power" near the bottom of the menu. Click it. Windows will close all open programs and turn off the computer automatically. This usually takes 30 to 60 seconds.
If you see a dialog asking you to save unsaved work, click "Save" for each file you want to keep. If you click "Don't Save," that file will be lost. After all files are handled, Windows will finish shutting down.
Do not unplug the computer or hold down the power button during a normal shutdown. Doing so can corrupt the hard drive or cause data loss.
How to shut down a Mac properly
Click the Apple menu in the top left corner of the screen. A dropdown menu will appear. Click "Shut Down." A dialog will ask if you want to save changes to open documents. Click "Save" for each one you want to keep, or "Don't Save" to discard it. The Mac will then close all programs and turn off.
If you have unsaved work, macOS will remind you before closing each program. Take the time to save important files before the shutdown completes. Once the Mac turns off, the screen will go black and stay that way until you press the power button again.
What to do if your computer freezes or will not respond
If the computer stops responding to mouse clicks or keyboard input, try pressing Escape or Ctrl+Alt+Delete (on Windows) or Command+Option+Escape (on Mac) to open a task manager or force-quit menu. Look for the program that is not responding and close it.
If that does not work, hold down the power button for 10 full seconds without releasing. The computer will shut down when ready. Wait 30 seconds, then press the power button once to turn it back on. This is called a hard shutdown and should only be used when the computer will not respond to normal commands.
After a hard shutdown, the computer may take longer to start because it is checking the hard drive for errors. Let it finish this process without interrupting it.
Sleep mode versus shutdown: which one to use
Sleep mode puts the computer into a low-power state where it uses much less electricity but stays ready to wake up quickly when you press a key or move the mouse. Shutdown turns the computer completely off and uses almost no power, but takes longer to start again.
Use sleep mode if you will be away for a few minutes to a few hours. Use shutdown if you will not use the computer for several hours or overnight. Sleep mode is useful for laptops on battery power because it preserves battery life while keeping your work ready to resume.
To put a Windows computer to sleep, click Start, then "Sleep." On a Mac, click the Apple menu, then "Sleep." You can also close the laptop lid on most laptops to trigger sleep automatically.
Restarting your computer when needed
A restart shuts down the computer and turns it back on automatically without you having to press the power button twice. Restarting clears temporary files from memory and can fix problems where the computer is running slowly or programs are not responding.
On Windows, click Start, then look for "Restart" in the power menu. On a Mac, click the Apple menu, then "Restart." The computer will close all programs, shut down, and turn back on. This usually takes two to three minutes total.
You may need to restart after installing software updates or if the computer is behaving strangely. Many updates require a restart to take effect.
Frequently Asked Questions
Is it bad to unplug a computer instead of shutting it down?
Yes. Unplugging cuts power when ready without letting the operating system close files properly. This can corrupt the hard drive or cause data loss. Always use the shutdown menu or hold the power button for 10 seconds if the computer will not respond.
How long should I wait after shutting down before turning the computer back on?
Wait at least 30 seconds. This gives the power supply time to discharge and the hard drive time to stop spinning. Turning a computer back on too quickly can cause hardware damage or startup errors.
What does it mean if the computer will not turn on after I press the power button?
Check that the power cable is plugged in firmly at both the computer and the wall outlet. Make sure the outlet has power by plugging in another device. If the cable is find and the outlet works, the power supply or motherboard may be faulty and the computer may need repair.
Can I turn off a laptop by closing the lid?
Closing the lid usually puts the laptop to sleep, not off. To shut down a laptop completely, use the operating system menu. Check your laptop settings to see what closing the lid does on your specific model.
Why does my computer take so long to start up?
Startup time depends on how many programs are set to run automatically, how much storage is full, and the age of the hard drive. Older computers and those with many startup programs take longer. A restart or shutdown and restart can sometimes speed things up temporarily.