ChromeOS Flex installation: Common problems and how to fix them

ChromeOS Flex is a free, lightweight operating system from Google that you can install on existing PCs and Macs to replace Windows or macOS. This article covers the most common installation problems and how to fix them.

Use this article if: 

• Your laptop won't boot from the USB key
• You see a blank screen or blinking cursor after booting
• You get an installation error message
• Your Mac shows a black screen after installation finishes

Before troubleshooting: Check that your device model is on the ChromeOS Flex certified models list. Variants of certified models can sometimes have hardware compatibility issues.

Problem 1: My laptop won't boot from the USB key

1. Make sure the laptop is fully powered off — not sleeping or in idle mode — before inserting the USB key.
2. Press the correct boot key for your laptop brand. The boot key is the keyboard shortcut you press immediately after powering on to access the startup menu. Check the boot key table in the ChromeOS Flex Installation Guide for your specific brand.
3. Try a different USB port. Some ports may not support booting.

1. Access the BIOS by repeatedly pressing the boot key for your laptop brand right after pressing the power button.
2. Look for an option called "USB Boot" or "Boot from External Media".
3. Make sure this option is enabled.
4. Save changes and exit BIOS.

Problem 2: I see a blank screen or blinking cursor after booting

Try these steps: 

• Check that your device model is on the ChromeOS Flex certified models list (your exact model variant may not be supported).
• Try a different USB port on your device.
• Test the USB key on another computer. If it boots successfully on another machine, the issue is with your original device's hardware compatibility.

Problem 3: "The installer could not find a valid destination to install"(error message)

Check internal storage capacity:

Your device's internal storage must be at least 16 GB

Check internal drive health:

Your internal drive must be functioning and not physically damaged

Reset and adjust BIOS storage settings:

1. Access BIOS by pressing your laptop's boot key repeatedly right after pressing the power button.
2. Reset BIOS to default settings.
3. Go to "Storage" settings.
4. Change the storage mode from "RAID" to "AHCI".

• RAID (Redundant Array of Independent Disks) is a mode in which multiple drives are combined into a single logical unit. ChromeOS Flex doesn't work with RAID mode
• AHCI (Advanced Host Controller Interface) is the standard, individual drive mode required by ChromeOS Flex.

5. Save changes and exit BIOS.
6. Retry the ChromeOS Flex installation.

Disable TPM if available: In BIOS, look for "TPM" (Trusted Platform Module, a hardware security chip) and disable it if the option is available.

Problem 4: "1962: No operating system found" (error message)

Step 1: Select the correct boot option

1. In the startup device menu, select "UEFI: [your USB drive name]". Make sure to select the option that starts with "UEFI:", not just the plain USB drive name

What is UEFI? UEFI (Unified Extensible Firmware Interface) is the modern firmware standard that manages how your computer's hardware and software communicate at startup. Older computers use BIOS; newer computers use UEFI. Both serve the same purpose.

1. Access BIOS by pressing your laptop's boot key repeatedly right after pressing the power button.
2. Find the "CSM" and "Boot Mode" settings.

What is CSM? CSM (Compatibility Support Module) is a legacy mode that allows modern hardware to run older software. It must be enabled for ChromeOS Flex installation.

3. Enable "CSM".
4. Set Boot Mode to "UEFI Only".
5. Save changes, exit BIOS, and retry the installation.

1. Access BIOS and reset to default settings
2. Press "ESC" while booting and select "UEFI: [USB drive name]".
3. After installation finishes, remove the USB drive.
4. Go back to BIOS and create a new boot option pointing to this path on your hard drive: /efi/boot/bootx64.efi
5. Save changes and reboot.

Problem 5: My Mac boots to a black screen after ChromeOS Flex installation

Option 1: Set the default boot option manually:

1. Remove the USB drive
2. Shut down the Mac completely
3. Power on and immediately hold the Option key to open the Mac startup manager
4. Select EFI Boot or ChromeOS Flex from the list of boot options
5. Hold Ctrl and click the option (or press Ctrl + Enter) to set it as the permanent default boot option

Option 2: Reset NVRAM/PRAM:

NVRAM (Non-Volatile Random-Access Memory) and PRAM (Parameter Random-Access Memory) store basic Mac settings such as volume, screen brightness, and startup disk selection. Resetting this memory can resolve boot issues after installing a new operating system.

1. Shut down the Mac completely
2. Hold "Cmd" + "Option" + "P" + "R" and press the power button
3. Keep holding the keys until you hear two startup chimes, then release

Can I switch back to Windows or macOS after installing ChromeOS Flex?

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