It is necessary to explain what dev mode is all about. This is not desirable for all, but allows greater control over your Chrome OS device. In short, this will explain how to enter dev mode, what is possible within dev mode, how to leave dev mode, and how to recognize if someone tampered with your computer to put it into dev mode.
Dev mode opens a whole new ecosystem to your Chrome OS device. On the Cr-48, it provides a command shell, and through that we can install new plugins (like Java), enable the GPS, boot Ubuntu, and many other things.
You can enter the shell by typing "ctrl+alt+t" and typing "shell".
To leave the shell, type "exit" until you see a browser window.
Under the battery of your Cr-48, you will find a switch hidden by a piece of tape. The following images show the tape, and the switch. Entering dev mode is as simple as flipping the switch.
Image credit: karen_2020 via Flickr
The sad computer is telling you that you are in dev mode. If you do not know why your computer is in dev mode, you should immediately flip the switch back.
You can bypass this screen with "ctrl+d" or it will pass it after 30 seconds.
Leaving dev mode:To leave dev mode, you must simply flip the switch back. Please reference "Entering Dev Mode" regarding the switch.
If you did too much with it, you may be asked to recover your computer. If this is the case, go to this link for directions. You will install the recovery to a USB drive and then simply insert it into the USB port on the machine to begin recovery.
The unofficial site for collaboration of ideas and knowledge for the Google Cr-48.