How can I perform a factory reset on a Chromebook?

This is a great troubleshooting step, because it resolves many types of bizarre, unexplainable errors and it only takes about 2 minutes. It is sometimes called a "powerwash" or a "device recovery". It will wipe the hard drive of the device, but this typically doesn't impact any users, because all user apps and data are stored in the cloud.
      For CTL Chromebooks:
    1. Simultaneously press Esc + refresh + power

    2. When it reboots to the screen which says "Please insert a recovery USB stick or SD card." enter Ctrl-d, then press Enter.

    1. Wait about 10 seconds then you will see a screen that says "Developer mode is disabled on this device by system policy...". Press Enter. You might also see another screen where you have to press the Space Bar.

  1. Wait about 10 seconds and it will boot to the normal login screen.
    Lenovo Chromebooks
  1. Simultaneously press Esc + refresh + power

  2. Use the Down Cursor Arrow key to highlight Advanced Options and press Enter.
  3. Press Enter to select Enable developer mode. Press Enter again to confirm.
  4. On the screen that says Confirm returning to secure mode, highlight Confirm and press Enter.