Fix: Default Boot Device Missing or Boot Failed

Make sure you disconnect any USB device before starting your PC

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Key notes

  • The default boot device missing or boot failed error signifies that your computer is unable to locate a device to boot from.
  • This can happen due to problems like incorrect boot sequence, misconfigured BIOS, and damaged boot files.
  • Alter the BIOS settings and activate the primary partition to resolve the default boot device missing or boot failed error on Levono and Acer laptops.
Default Boot Device Missing or Boot Failed

When the Lenovo or Acer laptop cannot detect the boot device on startup, it displays the Default Boot Device Missing or Boot Failed. Insert Recovery Media and Hit any key, Then Select Boot Manager to choose a new Boot Device or to Boot Recovery Media message instead of the startup screen.

If you are encountering this error on your PC, follow this guide to fix it.

What causes the default boot device missing or boot failed error?

If you see the default boot device missing or boot failed error during system boot, one or more of the following is likely to be the cause:

  • SATA cable – Defective or broken SATA cables cannot set up a successful connection.
  • Power supply – Insufficient power supply is a prevalent reason that can also set off several errors like the one at hand.
  • Incorrect boot sequence or boot order – If the BIOS settings are incorrect, the default boot device missing error is inevitable.
  • Inactive primary partition – If the primary boot partition is inactive, you may face the cause of the default boot device missing or boot failed error on Lenovo/Acer laptops.  
  • Unsupported hard disk drive – A defective, unsupported, or corrupt hard drive can also trigger this error. You can employ health check software to identify if there is a problem with HDD.

Fortunately, you can fix the non-bootable Lenovo/Acer device by implementing the reliable fixes below.

How do I fix the default boot device missing error in Lenovo/Acer?

Before employing the methods listed below:

  • Be mindful to disconnect any USB media from your PC. This is essential because, in such a scenario, your system will boot from the USB instead of the boot drive.

1. Change Boot Order and Boot Mode

  1. Restart your computer and immediately press the F10 or F12 key to access the BIOS settings.
  2. Navigate to the Boot menu in the Boot Setup window and check whether the Boot Hard Drive is detected. If yes, then set it as the priority using arrow keys.Default Boot Device Missing or Boot Failed
  3. Next, select Boot Mode and set it as UEFI instead of LEGACY.Default Boot Device Missing or Boot Failed
  4. After this, press F10 to save changes, exit BIOS and reboot your PC normally.

Incorrect boot order and boot mode prevent Windows from booting successfully. Changing the BIOS settings can resolve this startup error in Lenovo and Acer devices.

2. Activate the primary partition

  1. Boot your PC from the Windows installation media. If you don’t have one, refer to this guide to create Windows Installation Media with UEFI support.
  2. Select Repair your computer from the next screen.Default Boot Device Missing or Boot Failed
  3. Next, select Troubleshoot.Default Boot Device Missing or Boot Failed
  4. Choose Command Prompt from the Advanced options window.
  5. Type or paste the following commands one by one and press the Enter key.
    • diskpart
      list disk
      select disk 0
      list partition
      select partition 1
      active

      Default Boot Device Missing or Boot Failed
  6. When the current partition is marked as active, exit the command prompt window.

It is essential to set the primary partition as active otherwise, you will get the default boot device missing or boot failed error upon startup. You can also refer to this guide to rebuild the boot partition on Windows.

3. Run Startup Repair

  1. Insert the Installation media and boot your PC.
  2. Provide the necessary information and press the Next button.
  3. Select the Repair your computer option from the next screen.Default Boot Device Missing or Boot Failed
  4. Next, choose Troubleshoot.Default Boot Device Missing or Boot Failed
  5. Select Advanced options.Default Boot Device Missing or Boot Failed
  6. Choose the Startup Repair option from the Advanced options window.Default Boot Device Missing or Boot Failed

Now Startup Repair will scan your PC to diagnose the problem and resolve it. When the repair is completed, restart your computer, and hopefully, you will no longer get the default boot device missing or boot failed error.

If you get stuck in an automatic repair loop on Windows, the methods provided in this guide will help you deal with it.

4. Change the Store Controller Mode

Note icon NOTE
Changing the Storage controller mode may cause a loss of data. You are advised to back up or clone the disk before attempting this solution.
  1. Reboot your computer and immediately press the F10 or F12 key to access the BIOS Setup screen.
  2. Switch to the Storage tab using the right arrow key, select Storage Options using the downward arrow, and press the Enter key. Default Boot Device Missing or Boot Failed
  3. Use the arrow key to select SATA Configuration and set Configure SATA as AHCI.Default Boot Device Missing or Boot Failed
  4. Finally, press the F10 key to save changes and reboot your PC as you normally would.

Incorrect SATA emulation settings can cause errors of different sorts, including the default boot device missing or boot failed error during Windows PC startup.

You can try these methods to fix the default boot device missing or boot failed error on Acer/Lenovo laptops and those of other brands. If you get the ACPI BIOS error on Windows PC, try the solutions provided in this guide.

If you have any questions or suggestions, let us know in the comments section below.