Updating Chrome - Chromebooks
Click in the lower right hand corner
Select the time
On the pop-up screen, click on the gear(settings)
On the bottom left, select "About Chrome OS".
Under Google Chrome OS, you'll see which version of the Chrome operating system your Chromebook is using.
Select Check for Updates. If an update is available, it will start to download automatically.
After your download is down, select Restart to finish the update.