Most Chromebooks require you to remove a physical screw from the motherboard or disconnect the battery to enable flashing.
Flashing the BIOS is risky. A failed or incorrect flash can brick your motherboard. Ensure your laptop is plugged into AC power and stable. Do not interrupt the process. cbwinflashzip install
Do not close the program, open other applications, or shut down your computer during this process. Step 5: Finalization and Restart Most Chromebooks require you to remove a physical