Each time you turn on or use your Chromebook, it automatically checks for updates and installs them. Your Chromebook also lets you know when new updates are ready so that you'll always have the latest version of the operating system.
Install available updates
If your Chromebook sees available updates while you’re signed in, the system update icon will appear in the status area. Follow these steps to install the updates:
Click the status area in the lower-right corner where you see your account picture.
Select Restart to update.
Your Chromebook will shut down and automatically restart with the updates installed.
Check for updates
You can also check for updates if you want to install them sooner:
Click the status area in the lower-right corner where your account picture appears.
At the top of the page that opens, click About Chrome OS.
In the “About” window that appears, click the Check for and apply updates button.
Once any updates are done, you can look in the "About" window to confirm that your Chromebook is up to date.