Fixed: "Default boot device missing or failed to start" issue on Windows 10/11

Keynote:

• Discover 6 proven solutions to fix the "Default Boot Device Missing or Boot Failed" error and restore seamless booting on Lenovo and Acer computers.
• Employ the Partition Master tool for efficient MBR reconstruction, partition erasing, and other features to address boot issues.
• Master troubleshooting techniques such as adjusting boot order, setting an active partition, and using Windows Startup Repair to rectify the "Default Boot Device Missing or Boot Failed" error.

Are you dealing with the "Default Boot Device Missing or Failed" error on your Lenovo or Acer computer? If so, you're in the right place.

In today's era of modern computing, the reliability of devices is crucial for sustained productivity. However, in this fast-paced technological environment, unexpected failures can still plague you. One common issue is the "Default Boot Device Missing or Failed to Boot" error, which can hinder your computer operations.

Don't worry, though – tools like this one can reveal the underlying cause of such errors and offer useful tips on how to fix them.

How to solve the problem of missing or failed default boot device?

To address startup issues with a Lenovo or Acer laptop, we present six proven solutions before delving into their underlying causes. Review the table below to gauge the effectiveness and difficulty of each fix:

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If you know the cause of the problem, you can jump directly to the corresponding solution. Otherwise, please check the troubleshooting guide step by step.

Solution 1: Change the boot order and boot mode

Make sure the correct hard drive is set as the first boot device to ensure the machine starts up properly. To access the BIOS settings and change the boot order and mode if necessary, follow these steps:

Step 1. To access the BIOS settings, restart your computer and press the appropriate function key (F1, F2, or F12, depending on your device's support) while it's booting up.

Step 2: Make sure that your boot drive is listed in the main menu.

Step 3. If your drive is recognized, use the arrow keys to enter the "Boot Menu" and set your CD/DVD as the first boot preference.

Step 4. Select the correct boot mode according to your system type (Legacy for MBR systems, UEFI for GPT systems).

Step 5: Press F10 to save the changes and exit the BIOS.

Now, the system should boot successfully. Restart your laptop or computer and check if the failed to boot or missing default boot device issue is resolved.

If that doesn't work, try the next one.

Note: If you want to boot your laptop from USB, changing the boot order is a necessary step. Click the button below for a detailed guide:

Solution 2: Set the primary partition as active

A failed boot can occur if the primary partition containing Windows isn't marked as active. To fix the "Default boot device missing or failed" error, make sure the primary partition is set to active. But before you do that, create a Windows installation media first.

Here's how you can do it:

Step 1. Boot your computer from the Windows installation media (USB or DVD).

Step 2. Now choose “Repair your computer,” then “Troubleshoot,” and get to the Command Prompt.

Step 3: Type the "diskpart" command and press Enter.

4. Type the command “list disk” to identify your hard drive (for example, Disk 0).

Step 5. Select your drive with the command select disk X (replace X with the number of your disk).

Step 6: Type the list partition or list volume command and press Enter to view the available partitions.

7. Use the select partition X command to choose the primary partition, such as Partition 1.

Step 8: Type "active", and press Enter.

Step 9: Close the Command Prompt, disconnect the installation media, and then restart your system.

Please check if this solution has helped resolve your issue.

Read also: System cannot find any bootable devices

Solution 3: Rebuild the MBR of the startup disk

Rebuilding the MBR is crucial because it contains vital information needed to load the operating system. A corrupted MBR can lead to the error message "Missing Operating System" or "Boot Failure."

However, tools Partition Master can help you fix this issue quickly. It's a powerful third-party tool designed to solve MBR-related boot issues. It resolves master boot code problems with the "Rebuild MBR" tool, offers a user-friendly interface, and creates a WinPE boot disk for easy management and control of your computer's hard disks/partitions.

Step 1: Create a bootable WinPE disk

1. Launch AOMEI Partition Assistant, and click "Create Bootable USB" on the toolbar. 2. Click "Next" to finish the creation process.

Create a bootable disk

Step 2: Boot into Partition Wizard Bootable USB

Connect the bootable USB or CD/DVD to your computer. Restart your computer and press F2 or Del to enter the BIOS screen. Set it to boot from “Removable Device” or “CD-ROM Drive.” Partition Master will then run automatically.

Step 3: Rebuild the MBR

Click “Toolbox,” and then select “Rebuild MBR.”

Rebuild MBR

Select the disk and MBR type, then click “Rebuild”.

Rebuild MBR

You'll then see a message that the MBR for Disk X was successfully rebuilt.

By following the steps above, you can easily rebuild MBR and recover your system to completely solve the "default boot device missing or failed" issue. By downloading the Partition Master tool, as a comprehensive utility, it can also help with many other issues, such as:

• The computer has rebooted from a bugcheck
• Solving issues with unable to delete files from SD card
• Resolving the issue of Dell no bootable devices found

If you have any problems with your disk or computer startup, etc., you can seek help from the Partition Master tool.

Hopefully, that will resolve your issue. If not, try the next solution: Run a Windows Startup Repair.

Solution 4: Run Windows Startup Repair

Does the problem still persist? The solution is to perform a Windows Boot Repair. This method simplifies the process of fixing the “Default boot device missing or failed” issue. Just follow these steps:

Step 1. Boot the computer from the Windows installation CD or DVD.

Step 2: Choose your keyboard layout, language, time and currency formats, then click Next.

Step 3: Click on Repair your computer and then Troubleshoot.

Step 4: In the Advanced Options window, choose Startup Repair to fix startup issues.

Check if the issue has been resolved.

Solution 5: Run SFC to Repair Boot Files

If the repair startup fails, you can use the SFC command to handle corrupted boot files to resolve the issue of "Default boot device missing or failed boot."

Follow these steps:

Step 1: Boot from the Windows installation CD or DVD, choose "Repair your computer," then "Troubleshoot," and finally "Command Prompt."

Step 2: Run the "sfc /scannow /offbootdir=c: /offwindir=c:windows" command.

If that doesn't work for you, try the next one.

Solution 6: Erase your hard drive and reinstall the operating system

To regain control of your system, you need to find a lasting solution to the “Missing Operating System” or “Boot Failure” problem. Any underlying issues that might be causing the failure to boot can be resolved by getting rid of unnecessary files and starting over.

AOMEI Partition Assistant can maximize your system performance and handle any boot-related issues with ease. Its “Wipe Partition” option permanently deletes all data from a partition, ensuring that it cannot be recovered.

Here are the steps you need to follow:

We have two options for erasing your data. Choose the one you need.

Option 1: Erase Partition

1. Right-click the partition you want to wipe and select "Wipe." 2. In the new window, set the time you want to wipe the partition for, then click "OK." 3. Click "Execute 1 Task" in the bottom right corner, review your changes, and click "Apply."

Option 2: Erase Disk

• Select HDD/SSD, then right-click “Erase Disk.” • Set the number of times you want to overwrite the data (up to 10). Then click “OK.” • Click “Perform 1 Task” and then “Apply.”

After wiping the hard drive, you can reinstall the operating system.

Read more:

#2 What can cause the default boot device to be lost or fail to boot?

Many users report that their computer won't turn on. Instead, their Windows device shows a blue “Default Boot Device Missing or Boot Failed” screen. This error occurs when the computer or laptop can't find or load the Windows boot files.

If you are among those affected, you should know the reasons listed below:

• Incorrect startup sequence or order.
• Incorrect BIOS configuration.
• Hard drive failure.
• Damaged or missing boot files.
• Issues with the Boot Configuration Data (BCD) or Master Boot Record (MBR).
• Damaged or disconnected data cables.
• Failed operating system updates or upgrades.

Regardless of the reason behind the startup failure, you should be able to find the right solution in this article. If you find this guide helpful, please share it with others who might need it using the social buttons below.

Conclusions

Congratulations! You are now armed and ready to tackle the annoying “Missing Operating System” or “Boot Failure” issues. Among these powerful utilities, the “Rebuild MBR” function of Partition Master has proven to be a reliable ally in dealing with boot-related problems.

This user-friendly tool makes disk and partition management easy, allowing you to get your device up and running quickly.

So, what are you waiting for? Rely confidently on the capabilities of a reliable Disk Partition Master Tool and leverage these solutions effortlessly to fix the “Default Boot Device Missing or Failed” error in your computing journey.

Frequently Asked Questions (FAQs) on "Missing or Failed Boot Default Device"

Are there any other issues? No need to look further! Here are some common questions for your reference:

How to fix the 'Default Boot Device Missing or Failed' issue on a Lenovo laptop?

You can do this through the BIOS settings.

Step 1. Restart and enter the BIOS setup (by pressing F1/F2).

Step 2: In the Main menu, confirm that the correct boot drive is selected.

Step 3: Set it as the first boot option in your BIOS menu.

Step 4: Choose either Legacy or UEFI boot mode.

Step 5: Save the changes and exit (F10).

Restart your laptop, and that should do it.

2. What can cause a laptop to fail to start up correctly?

A failed startup can be caused by incorrect boot order in the BIOS, a problem with the BIOS settings, a hard drive failure, missing boot files, or issues with the Master Boot Record (MBR) or Boot Configuration Data (BCD).

3. How to Repair the Boot Manager on a Laptop?

You can use Windows Startup Repair:

Step 1: Boot to the Windows installation disc.

Step 2: Select "Repair your computer," then choose "Troubleshoot," and then "Startup Repair."

Step 3: Follow the on-screen instructions to have Windows try to fix it automatically.