What a complete restart does and when you need one

A complete restart closes every program, clears your computer's working memory, and starts the operating system fresh from the beginning. It is different from putting your computer to sleep or shutting it down without restarting — those leave some processes running or incomplete. A full restart stops everything, clears the RAM, and reloads Windows or macOS from scratch.

You need a complete restart when your computer is running slowly, programs are freezing, or you have installed new software or updates that require a restart to take effect. A restart also clears temporary files and resets network connections, which fixes many problems that a straightforward close-and-reopen cannot.

The process takes a few minutes from start to finish. During that time, your computer will be unavailable, so save your work first.

Key Takeaways

  • Save all open work before you restart, because all programs will close and any unsaved changes will be lost.
  • On Windows, use the Start menu and select Restart, or press Ctrl+Alt+Delete and choose Restart from the menu.
  • On Mac, use the Apple menu, select Shut Down, and check the "Reopen windows when logging back in" box to restore your session.
  • A complete restart clears your computer's memory and reloads the operating system, which fixes slowness and freezing that closing programs alone cannot.
  • If your computer will not restart normally, hold the power button for 10 seconds to force a shutdown, then press it again to turn it back on.

How to restart on Windows

The easiest way to restart Windows is through the Start menu. Click the Start button in the lower left corner, then click the power icon (it looks like a circle with a line at the top). A menu will appear with three options: Sleep, Shut down, and Restart. Click Restart.

Your computer will close all open programs and windows without warning, so make sure you have saved everything first. The screen will go dark, and you will see text or a spinning circle as Windows shuts down and starts back up. This usually takes one to three minutes. When you see the login screen, your restart is complete.

If the Start menu is not responding, use the keyboard shortcut instead. Press Ctrl+Alt+Delete at the same time. A menu will appear with several options. Click the power icon in the lower right corner, then select Restart from the menu that appears.

How to restart on Mac

On a Mac, click the Apple menu in the upper left corner of the screen. A dropdown menu will appear. Click Shut Down. A dialog box will ask you to confirm. Before you click Shut Down in that box, check the box that says "Reopen windows when logging back in" — this will restore your open programs and windows after the restart, so you do not have to open them again by hand.

Click Shut Down. Your Mac will close all programs and turn off. Wait a few seconds, then press the power button to turn it back on. You will see the Apple logo and a progress bar. The startup process usually takes one to two minutes. When you see the login screen, enter your password and log in.

If you want to restart without restoring your previous windows, skip the checkbox and just click Shut Down. Your Mac will start fresh with no programs open.

Force a restart if your computer is frozen

If your computer is completely frozen and will not respond to clicks or keyboard commands, you can force it to shut down. On Windows, hold the power button on the front or side of your computer for 10 seconds without letting go. The screen will go black and the computer will turn off. Wait 10 seconds, then press the power button once to turn it back on.

On a Mac, hold down the power button for 10 seconds. The screen will go dark. Wait a few seconds, then press the power button again to restart. A forced shutdown will not give your programs a chance to save their work, so you may lose unsaved changes in open files. Use this method only when the normal restart process does not work.

What to do before you restart

Before you restart, save all your work. Open each program that has unsaved files — your web browser, text editor, spreadsheet, email client, or anything else you have been using — and save or close each file. If a program asks whether you want to save changes, click Yes or Save.

Close any downloads that are in progress. If you are downloading a large file, wait for it to finish or pause it and resume after the restart. A restart will interrupt downloads and may corrupt the file.

If you are working with an external hard drive, USB stick, or network drive, close any files on those devices and eject them properly before restarting. On Windows, right-click the device in File Explorer and select Eject. On Mac, drag the device icon to the Trash or right-click it and select Eject.

What happens during a restart

When you start a restart, your operating system sends a signal to all open programs to close. Most programs will close when ready. If a program does not close within a few seconds, the operating system will force it to close without saving. This is why saving your work first is important.

Once all programs are closed, the operating system shuts down. Your computer clears its RAM (the fast, temporary memory it uses while running), and the hard drive stops. The screen goes dark.

When you press the power button or after a few seconds on Mac, the computer powers back on. The operating system loads from your hard drive into RAM, checks that all hardware is working, and displays the login screen. At this point, the restart is complete and your computer is ready to use.

Restart versus shutdown versus sleep

A restart shuts down the operating system completely and starts it again. A shutdown closes the operating system and turns off the computer, but does not start it again — you have to press the power button to turn it back on. A sleep mode keeps your computer powered on but uses very little electricity; your programs stay open in memory, and the screen turns off. When you move the mouse or press a key, the computer wakes up in seconds with everything still open.

Use sleep if you are stepping away for a few minutes or an hour. Use shutdown if you are done for the day and will not need the computer again soon. Use restart when you have installed updates, when programs are freezing, or when your computer is running slowly and you want to clear its memory and reload the operating system.

Frequently Asked Questions

Will restarting delete my files?

No. A restart closes all programs and clears the computer's working memory, but it does not delete files on your hard drive. All your documents, photos, and programs will still be there after the restart. Only unsaved work in open programs will be lost.

How long does a complete restart take?

A restart usually takes two to five minutes from the moment you click Restart until you see the login screen. Older computers or computers with many programs installed may take longer. If your restart takes more than 10 minutes, something may be wrong — restart again or contact your computer's manufacturer.

Can I restart my computer while it is updating?

No. If Windows or macOS is installing an update, do not restart or shut down. Let the update finish. If you interrupt an update, your operating system may not work correctly. If an update is taking a very long time, wait at least 30 minutes before assuming something is wrong.

What if my computer will not turn back on after I restart?

Wait a full minute after the screen goes dark — the startup process may still be running. If the screen is still dark after a minute, press the power button once. If nothing happens, hold the power button for 10 seconds to force a shutdown, wait 10 seconds, then press the power button again to turn it on. If your computer still will not start, contact the manufacturer or a repair technician.

Do I need to restart after installing software?

Not always. Many programs work when ready after installation. However, some programs and all operating system updates require a restart to work correctly. If the installer shows a message asking you to restart, do so. If you are not sure, restarting will not hurt and may prevent problems later.