If you find your Chromebook is playing up and you need to reset it to factory defaults, then you need to as Google calls it "Powerwash" it. This removes any local saved settings and preferences but wont loose your documents or apps as there saved in the cloud - Smart!
To Powerwash your Lenovo Chromebook follow these steps below.
Switch off the Chromebook
Next press and hold the following keys "Esc + Refresh Key + Power".
The Chromebook will turn on and display a yellow exclamation mark.
Press the keys "Ctrl + D" to enter developer mode, now press the "Enter" key, the screen should display a red exclamation point.
Next press "Ctrl + D" and then "Enter". The Chromebook starts the wiping process which can take a few minutes.
Once complete press the "Space bar" and then "Enter". That’s It!
If you want to enroll the Chromebook to a domain, once its restarted just press "Ctrl + E" and enter a domain username and password - simples!