How to Troubleshoot and Fix Windows Server Inaccessible Boot Device Error

Encountering the Inaccessible Boot Device error, coded as 0x0000007b, is a common yet critical issue that manifests as a blue screen of death, often following a Windows update or system reset. This guide delineates five effective methods to rectify the Inaccessible Boot Device on Windows Server 2019.

Understand the Inaccessible Boot Device Error

The Inaccessible Boot Device error is prevalent stop code that indicates Blue Screen problem on Windows Server platforms including versions 2019, 2022, 2016, and 2012. This error shows when the operating system unable to access system partition during startup, prompting protective shutdown to prevent potential data corruption.

Root Causes of the Inaccessible Boot Device Error

The error may stem from various sources, such as:

• Corrupted boot partition files
• File system corruption
• Bad sectors on the OS hard drive
• Changes in BIOS storage controller settings
• Faulty motherboard or storage hardware
• Hardware conflicts due to new installations
• Software conflicts from recent installations
• Damaged Master Boot Record or missing Boot Configuration Data

Solutions for the Inaccessible Boot Device Error

The appropriate fix hinges on the underlying cause. The following sections will explore the main causes, solutions, and a backup strategy for data protection and disaster recovery. The goal is to provide a clear path to resolving the error and safeguarding server integrity.

Solution 1: Ensure Boot Disk Connectivity and Accessibility

Verifying the connection and accessibility of the boot disk is a fundamental step when faced with the Inaccessible Boot Device error on Windows Server 2019. Here’s how to confirm that your server’s boot disk is properly detected:

1. Power on the server and interrupt the boot sequence when the loading animation appears by shutting it down.
2. Repeat the interruption twice more, and on the third attempt, the server will enter Recovery mode.
3. Select ‘See advanced repair options’ and then ‘Troubleshoot’.
4. Choose ‘Command Prompt’ and log in using the Admin account.
5. Type the following command and press Enter: diskpart
6. Enter the following command  to display all connected disks and verify the system disk’s presence: list disk
7. Type the following command to to list all volumes and ensure the boot device is recognized:list vol

If the system disk does not appear, it’s advisable to seek support from the Original Equipment Manufacturer (OEM) or the provider of the virtualization platform for further technical assistance. This step is crucial to rule out hardware connectivity issues before delving into more intricate troubleshooting procedures.

Solution 2: Revert Recent Updates

To mitigate the Inaccessible Boot Device error, a rollback of recent updates may be necessary. Here’s a streamlined process:

1. Initiate the server’s boot sequence and interrupt it once the loading indicators appear by powering off the server.
2. Repeat the boot interruption process twice more. On the third attempt, the server will enter Recovery mode.
3. In Recovery mode, navigate to ‘See advanced repair options’ followed by ‘Troubleshoot’.
4. Select ‘Command Prompt’ and authenticate with the Admin account credentials.
5. Within Command Prompt, execute the command the following command to load the registry hive: reg load HKLM\temp c:\windows\system32\config\software
6. Proceed to remove the SessionsPending registry key by executing: reg delete "HKLM\temp\Microsoft\Windows\CurrentVersion\Component Based Servicing\SessionsPending" /v Exclusive
7. Confirm the deletion when prompted by typing ‘Y’ and pressing Enter.
8. Unload the modified registry hive using: reg unload HKLM\tem
9. Create a directory to isolate problematic updates with: MKDIR c:\temp\BadUpdates
10. List all installed updates using the following command and identify those with an ‘Install Pending’ status:  dism /image:C:\ /get-packages
11. For each update marked ‘Install Pending’, execute the following command, substituting ‘Package-Identity’ with the actual name of the update. dism /image:c:\ /remove-package /packagename:Package-Identity /scratchdir:c:\temp\BadUpdates

This procedure aims to eliminate updates that may be causing boot disruptions, thereby restoring server functionality.

Solution 3: Remove Recent Drivers and Software in Safe Mode

To rectify the Inaccessible Boot Device error, it’s essential to consider uninstalling newly installed drivers or software that might be causing the issue. Here’s how to proceed:

1. Power on the server and interrupt the boot sequence when the loading indicators appear by shutting it down.
2. Repeat the boot interruption twice more, and on the third attempt, the server will enter Recovery mode.
3. Select ‘See advanced repair options’ and then ‘Troubleshoot’.
4. Select ‘Startup Settings’ and opt for ‘Restart’.
5. After the server restarts, it will present the Advanced boot options. Select Safe Mode using the arrow keys and confirm by pressing Enter.
6. Once the server boots in Safe Mode, sign in as usual and proceed to uninstall any device drivers or software that were recently added.

The presence of “Safe mode” on the screen corners confirms that the server is in the correct mode for this operation. This step is crucial for eliminating any recent changes that may interfere with the server’s boot process.

Solution 4: Repair the Master Boot Record with BootRec Commands

To correct the Inaccessible Boot Device error, the BootRec command can be utilized to repair the Master Boot Record (MBR). Here is the procedure:

1. Power on the server and interrupt the boot sequence when the loading animation appears by shutting it down.
2. Repeat the interruption twice more, and on the third attempt, the server will enter Recovery mode.
3. Select ‘See advanced repair options’ and then ‘Troubleshoot’.
4. Choose ‘Command Prompt’ and log in using the Admin account.
5. Once in Command Prompt, input the following command and press ENTER: BOOTREC /FIXMBR
6. If the operation is successful, restart the server, which should now boot normally.
7. Execute the following command  to write a new boot sector if the current one is damaged:
8. Bootrec /fixboot
9. If an error such as “Boot Manager is Missing” appears, execute the following command to rebuild the MBR: BOOTREC /RebuildBcd

This process aims to resolve issues with the boot record, which is a common cause of boot-related errors on Windows servers.

Solution 5: Activate Last Known Good Configuration for Recovery

The Last Known Good Configuration (LKGC) is a recovery feature in Windows system to revert to stable state before recent changes were made.

1. Power on the server and interrupt the boot sequence when the loading indicators appear by shutting it down.
2. Repeat the boot interruption twice more, and on the third attempt, the server will enter Recovery mode.
3. Select ‘See advanced repair options’ and then ‘Troubleshoot’.
4. Select ‘Startup Settings’ and opt for ‘Restart’.
5. After the server restarts, it will present the Advanced boot options.
6. Use the arrow keys to select ‘Last Known Good Configuration (Advanced)’ and press Enter.

This action can resolve issues caused by unsuccessful updates or new software and driver installations, restoring the server to its last operational configuration.

Solution 6 Conduct System and Disk Scans with SFC and Chkdsk

If the server continues to display the Inaccessible Boot Device error, it’s advisable to inspect the boot partition for errors. Utilize the Command Prompt to perform system and disk scans:

1. Power on the server and interrupt the boot sequence when the loading animation appears by shutting it down.
2. Repeat the interruption twice more, and on the third attempt, the server will enter Recovery mode.
3. Select ‘See advanced repair options’ and then ‘Troubleshoot’.
4. Choose ‘Command Prompt’ and log in using the Admin account.
5. Once in Command Prompt, input the following command and press ENTER to initiate a scan and repair of the drive:
   chkdsk /f /r X: Note: replace x with the actual drive letter.
6. Next, deploy the System File Checker (SFC) tool to identify and fix corrupted Windows system files by entering the following command: sfc /scannow

These steps will help diagnose and potentially resolve issues with the file system and hard drive that could be causing the boot error.