Before ChromeOS devices are enrolled, and before users sign in, the device downloads any critical updates. Critical updates don't always include the latest version updates.
After enrollment, devices update to the latest Chrome version by default. If you set auto-update policies, your policies apply after enrollment. For options and additional information, see Manage updates on ChromeOS devices.
If you're setting up a small number of devices, you don't need to complete this step. Just enroll your devices and let them automatically update to the latest Chrome version when you first sign in.
If you're setting up a large number of devices and want to conserve network bandwidth, we recommend updating the Chrome version before enrolling the devices.
To update your devices to the latest version of Chrome, you can remove and reinstall the ChromeOS. It can take as little as 5 minutes to over 20 minutes to install the latest version, it just depends on the device. For details, see Recover your Chromebook.
Note: Use 4 GB or larger USB 2.0 drives to build the recovery stick.