Fix INACCESSIBLE_BOOT_DEVICE BSOD Error on Lenovo/HP/ASUS Easily

April 18, 2018

You may get INACCESSIBLE_BOOT_DEVICE error after installing Windows 10 on SSD or just Windows updates. Find solutions on how to fix the error on Lenovo, HP, or ASUS laptop here.

INACCESSIBLE_BOOT_DEVICE BSOD Error

“Hello. I’d like to say this is a little bit strange because I get the error just in the process of working. The screen stills for nearly one second and gives following interface reading ‘Your PC ran into a problem and needs to restart. We’re just collecting some error info, and then we’ll restart for you. (0% complete)’. There is a line beneath with a smaller font size saying ‘if you’d like to know more, you can search online later for this error: INACCESSIBLE_BOOT_DEVICE.’ So, what’s wrong? Why would my boot device becomes inaccessible?”

Inaccessible Boot Device Lenovo

Search online, you may find there are many users are in the same trouble. Some of them encounter inaccessible boot device on Lenovo ThinkPad laptop, some of them on HP Pavilion, and some on ASUS, SONY VAIO, Toshiba, and so on. The background OS also varies from Windows XP to Windows 10, and mostly on Windows 10. What does the INACCESSIBLE_BOOT_DEVICE error mean and when would it happen?

When Does Inaccessible Boot Device Error Occurs?

INACCESSIBLE_BOOT_DEVICE usually comes with Blue Screen of Death (BSOD) error in Windows, with the declaration that the PC cannot boot normally. According to users’ feedback, this error happens mostly in following situations.

  • Inaccessible boot device after Windows Update. The error is likely to emerge after you installing Windows latest updates in a period of time.

  • Inaccessible boot device after installing Windows 10 on SSD. No matter you clean install Windows 10 on SSD or migrate Windows 10 to SSD, the error means there is something wrong about the system files on the boot SSD. You may have missed something during installation or cloning.

  • Inaccessible boot device after system partition resized. Likewise, inappropriate operations may damage system files and lead to this type of errors. If you’d like to resize system drive, please refer to how to partition C drive properly.

  • Inaccessible boot device after BIOS update.

Except for covering situations, the error also happens on a damaged hard disk, i.e. a disk with many bad sectors on. In some cases, the error displays for seconds and then the PC restarts automatically. However, the error occurs once again on the restart. It is also called boot device restart loop. Then, what should you do to get this type of inaccessible boot device fixed?

Fix Inaccessible Boot Device BSOD Error with Different Solutions

To fix the problem that caused by different factors, you need to take measurements accordingly. If it is caused by BIOS update, you can revert to previous BIOS settings. If it is caused by Windows 10 installation, perform a clean install or Windows cloning once again. If it is caused by other elements like Windows Update or bad sectors, check these methods out to see if they are helpful.

Fix Inaccessible Boot Device with Installation Disc

If you have a Windows installation disc or repair disc, you can tell Windows back to a state when it works fine.

  1. Insert the disc to your Lenovo PC or any PC has the error and then boot off. You may need to change boot order in BIOS if it falls back to the internal disk.

  2. At the installation interface, choose language, time and keyboard input and click Next.

  3. Click on Repair your computer in the lower-left corner.

  4. Click on System Restore in Advanced Tools. Then, let it recover Windows to a previous System Restore point.

  5. After successful boot up, type services.msc in Run to open Services. Find Windows Update, right click it and choose Stop to prevent Windows from updating, so that you can avoid such error in the future.

Most Windows PCs create system restore points by default. To fix ASUS laptop inaccessible boot device error or the like, it could be the easiest way. If the error still cannot be solved due to unknown causes, you may want to try fixing the problem by restoring Registry Backup.

Fix Inaccessible Boot Device via Registry Backup

It is little-known that the operating system keeps a backup of a working Registry for recovery purposes. If you don’t have a system backup around, you can manually restore Windows to a working state.

  1. Start your computer with Advanced startup options, and then go Troubleshoot > Advanced options > Command Prompt. The command prompt should start on X: \Windows \System32 if you run it as administrator.

  2. Type D: \ (Windows will be moved to another partition with a different drive letter in this mode, usually D drive. but you can type dir to verify if you’re in the correct drive. If you are, you should see the contents of Windows OS).


    D Directory

  3. Type cd D: \Windows \System32\ (enter into the System32 folder).

  4. Type mkdir configBak (create a folder to temporary backup of files on the config folder).

  5. Type copy config configBak (create a temporary backup of the files in the config folder).

  6. Type cd config\RegBack (move inside the RegBack).

  7. Type dir (verify the content of the RegBack folder, the size of those files should be similar to the ones in this picture. If any of the files shows 0, there is no backup available. In other words, you cannot repair inaccessible boot device in this way.).


    Registry Backup Directory

  8. Type Copy * ..\* (copy the files from the RegBack folder to the config folder). Close the Command Prompt to complete the task and restart your PC.

Tips: if the Windows on your PC is not on D drive in that mode, you need to replace D with the correct drive letter in all related steps.

Repair Corrupted System Files by Rebuilding MBR

If aforementioned solutions still don’t work in your case, or you don’t want to restore to previous state in the event of corrupted system files, you can repair the error by rebuilding a MBR.

AOMEI Partition Assistant Standard is free partition manager that can assist you fix inaccessible boot device on HP PC or the like in Windows 10/8/7/XP/Vista by rebuilding the corrupted MBR. Free download to have a try.

Preparations:

  • A fine PC. A computer used to install AOMEI Partition Assistant on and create bootable media.

  • A USB flash drive or CD/DVD. A media used to make bootable media.

1. Connect the media to the fine PC. Install and run AOMEI Partition Assistant on that computer, too.

2. At main interface, click on Make Bootable Media in the left Wizards. Then, follow the wizard to complete.

Make Bootable Media

3. Insert the bootable media to your PC that has inaccessible boot device error and start off. You’ll see AOMEI Partition Assistant again once login.

4. Right click the disk you want to repair and click on Rebuild MBR from the menu.

Rebuild MBR

5. In the pop-up window, choose the proper MBR type for your Windows.

Choose MBR Type

6. Click Apply and then Proceed to commit the task. Finally, restart your computer.

Tips: AOMEI Partition Assistant Standard also supports check errors for hard drive and partitions. Surface Test and Check Partition features are available in the event of bad sectors. For detailed information, please refer to check hard drive for errors in Windows 10.

Summary

When your PC encounters INACCESSIBLE_BOOT_DEVICE BSOD error in Windows 10/8/7, you can solve the problem by restoring system points, restoring registry backup, or fixing corrupted MBR with the help of different tools.

AOMEI Partition Assistant Professional, the advanced version of Standard, provides more powerful features. For example, you can transfer OS to GPT SSD disk without reinstalling if current disk is about to fail.