By default, your Chrome notebook uses the beta version of Chrome OS.

Switch to the development channel

The version in the development channel houses features that are still being built. You're welcome to try it out, but be aware that things may not always work as expected.

To switch to the development channel, follow these steps:

1.) Sign in to your account on the main sign-in screen.
2.) Click the wrench icon on the browser toolbar.
3.) Select About Chrome OS.
4.) Click More info in the first section on the "Chrome OS" page that appears.
5.) Select "Development" from the menu in the "Channel" section.

The next time the system updates, you'll be switched to the development channel.

Switch to the beta channel

To switch back to the beta channel from the development channel, return to the "Chrome OS" page and use the menu in the "Channel" section.

You won't be switched to the beta channel until the beta channel updates to a version that is newer than the version you're currently on.



Source: Google.com