Your computer's operating system is the main software that makes your computer work. On most PCs, that operating system is Microsoft Windows. On a Mac, it is macOS.
Keeping that software updated is one of the simplest things you can do to improve your computer's security. Updates can fix security weaknesses, correct problems, and improve the reliability of your computer.
You do not need to be a computer expert to install them. This guide walks you through the process one step at a time.
Before you start
Take a few simple precautions before installing an operating system update:
- Save your work. Close or save important documents because your computer may need to restart.
- Plug in your laptop. Do not risk losing power during an update.
- Connect to the internet. Updates normally need to be downloaded before they can be installed.
- Back up important files. Major problems are uncommon, but having a current backup is always a good habit.
- Allow enough time. Some updates install quickly, while larger updates can take longer and may restart the computer more than once.
How to update Windows 11
Windows 11 normally downloads and installs important updates automatically, but it is still a good idea to check Windows Update periodically.
Step 1: Open Settings
Click the Start button on the taskbar, then select Settings.
Step 2: Open Windows Update
In Settings, select Windows Update.
Step 3: Check for updates
Select Check for updates. Windows will check Microsoft's update service for updates that are available for your computer.
Step 4: Download and install
If Windows finds updates that need your approval, select Download & install. Windows will download and begin installing them.
Step 5: Restart when requested
Some updates require a restart before installation is complete. Save anything you are working on and select the restart option when you are ready.
After the computer restarts, return to Settings > Windows Update. If Windows says that you are up to date, you are finished.
Still using Windows 10?
Important: Microsoft's standard free support for Windows 10 ended on October 14, 2025. That means a normal Windows 10 installation no longer receives the same free ongoing security support it received before that date.
If your computer still uses Windows 10, check whether it can run Windows 11. Open Windows Update and check for updates. Microsoft may tell you whether the computer is eligible for the Windows 11 upgrade.
If your computer cannot run Windows 11, consider your supported security options or replacing the computer rather than assuming an old operating system is safe simply because the computer still works.
How to update a Mac
Apple provides macOS updates through Software Update. Software Update shows software that is compatible with your particular Mac.
Step 1: Open System Settings
Click the Apple menu in the upper-left corner of the screen and choose System Settings.
Step 2: Open General
In the System Settings sidebar, click General.
Step 3: Open Software Update
Click Software Update. Your Mac will check for software that is available and compatible with your computer.
Step 4: Install the available update
If an update or upgrade is available, follow the button shown on the screen, such as Update, Upgrade, or Restart Now.
Your Mac may ask for the administrator password you use to sign in.
Step 5: Let the installation finish
Allow the update to complete. Your Mac may restart, display a progress bar, or briefly show a blank screen during installation. If you use a MacBook, keep it connected to power and do not close the lid while the update is installing.
When Software Update says your Mac is up to date, no newer compatible update is currently being offered for that Mac.
Should automatic updates be turned on?
For most everyday computer users, automatic security and operating system updates are a good idea. They reduce the chance that an important security fix will be forgotten.
On Windows 11, Windows Update automatically handles important updates. You can review its options under Settings > Windows Update.
On a Mac, open System Settings > General > Software Update and review the automatic-update options. Keeping security updates and system files current is especially important.
What if an update will not install?
Do not panic if an update fails the first time. Start with these simple checks:
- Restart the computer and try again.
- Make sure the internet connection is working.
- Make sure the computer has enough free storage space.
- Keep a laptop connected to power.
- Return to Windows Update or Software Update and check again.
If the update repeatedly fails, use the official Microsoft Support or Apple Support website for troubleshooting rather than downloading an update from an unfamiliar website.
Know Phishing Safety Tip: Be careful with fake update warnings
Scammers sometimes use fake security warnings and fake software-update messages to frighten people into clicking a link or downloading a program.
You do not need an unexpected email, text message, advertisement, or website pop-up to check whether Windows or macOS needs an update.
Instead, check directly on the computer:
- Windows 11: Start > Settings > Windows Update
- Mac: Apple menu > System Settings > General > Software Update
If a website suddenly announces that your operating system is infected or urgently needs an update, do not install software from that message. Close the page and check for updates through the computer's built-in settings.
The Know Phishing takeaway
Operating system updates are routine computer maintenance, but they are also an important part of staying safe online.
Keep your computer updated, use the update tools built into Windows or macOS, and do not trust unexpected messages telling you to download an update from somewhere else.