5 Solutions to “Server 2016 Inaccessible Boot Device” Issue

What does “inaccessible boot device” mean in Server 2016?

"I was working on my Windows Server 2016 on Friday and everything was working fine. The last thing I did was to update the OS. Now this morning the Server was down. I rebooted it several times, but when the Windows loading logo is on the screen, it hangs for about 5 minutes then it shows the Blue screen of death. The error is “inaccessible boot device”. What should I do to repair this Server 2016 inaccessible boot device error?"

The “Inaccessible Boot Device” is a common error or stop code that appears as a reference when you meet Blue Screen problem on Windows Server 2016 and Windows Server 2008/2012/2019. This error usually means that the Windows Server 2016 operating system has lost access to the system partition during startup. When it occurs, the system will shut itself down and show a Blue Screen or Stop Error to protect itself from potential data corruption or loss.

Possible causes of Server 2016 inaccessible boot device error

Most Server 2016 reported that this issue happens after Server 2016 updates pushed by Microsoft. Besides, the following factors can also lead to “Inaccessible Boot Device” error:

♦ Corrupted files in the boot partition;
♦ System files corruption;
♦ Bad sector on your main hard drive;
♦ The storage controller mode or settings in the BIOS are changed;
♦ A faulty motherboard or storage controller or faulty hardware;
♦ Newly-installed hardware conflicting with other devices;
♦ Newly-installed software incorrectly written or conflicting with other programs;
♦ Corrupted Master Boot Record or missing Boot Configuration Data.

5 Solutions to "Server 2016 inaccessible boot device" error

Here are a few inaccessible boot device repair methods you can try to resolve this error in Server 2016, 2019 or other Server OS. See what applies in your case.

• 1. Roll back recent Server update

• 2. Boot your Server into Last Know Good Configuration

• 3. Check the boot partition for errors via Command Prompt

• 4. Check the system files integrity

• 5. Repair damaged MBR/BCD

▶ Solution 1. Roll back recent Server update

If you meet the issue: inaccessible boot device in Server 2016 after update, you can try to roll it back. Complete steps are:

Step 1. Press the power button to boot your Server. When the White circles start displaying, press the power button to power off the Server.

Step 2. Interrupt the Server boot 3 consecutive times to initiate “Preparing Automatic Repair”.

Tips: if you fail to enter recovery mode via this method, you might need to use Server 2016 installation DVD or CD.
1. Insert the installation media into your server and change your boot order to boot from the media.
2. Power up your Server and wait for “press any key to boot from CD or DVD” screen to appear, and press any key to continue.
3. At the Windows Boot Manager, select “Windows Setup [EMS Enabled]” and hit on “Enter” key on your keyboard.
4. At the Windows Server 2016 installation screen, click “Next”.
5. Then click on “Repair your computer” to access the “Choose an option” window, and select “Troubleshoot”.

Step 3. Then you will get to the Recovery Mode, click “Troubleshoot” from the given recovery mode options.

Step 4. Choose “Command Prompt” in the advanced options, and then click the “Admin” account to load Command Prompt.

Step 5. Input the password for the administrator account and click “Continue” to open Command Prompt window.

Step 6. In the elevated Command Prompt window, input the following commands in turn and press “Enter” after each one.

● reg load HKLM\temp c:\windows\system32\config\software: to load Windows registry to HKLM/temp.
● reg delete "HKLM\temp\Microsoft\Windows\CurrentVersion\Component Based Servicing\SessionsPending" /v ● Exclusive: to delete the SessionsPending registry key. When you are prompted to confirm, type “Y” and press Enter.
● reg unload HKLM\temp: unload the Windows registry
● MKDIR c:\temp\BadUpdates: to create a temp folder to hold the unnecessary Windows Server updates.
● dism /image:C:\ /get-packages: list all installed updates.

Step 7. Now we need to execute other commands to delete the “Install Pending” Packages which might be real culprit behind the “Server 2016 inaccessible boot device”.

Note: before running the command below, check out the list of the result for packages with “Install Pending” status and note their Package Identity.

● dism /image:c:\ /remove-package /packagename:Package-Identity /scratchdir:c:\temp\BadUpdates: replace the Package-Identity with the package name in your situation.

Now you can check if the problem is solved. If not, proceed to the next method.

▶ Solution 2. Boot your Server into Last Know Good Configuration

Last Known Good Configuration, known as LKGC, is a recovery option Microsoft built-into all versions of Windows. With that, you can recover Windows PC or Server to the last good status if you are having trouble starting it normally after a failed update, driver installation or software setup. It can be accessed from “Advanced Boot Options”.

Step 1. Refer to the fix 1 above to enter “Advanced Options”, and click “Startup Settings”.

Step 2. When the “Startup Settings” screen appears, click “Restart”.

Step 3. Then you will see the “Advanced Boot Options” screen. Use the keyboard to navigate to “Last Known Good Configuration (Advanced)” and press the “Enter” key.

▶ Solution 3. Check the boot partition for errors via Command Prompt

If the “Server 2016 inaccessible boot device” persists, try to check the boot partition for possible bad sector using Command Prompt. To do this, you just need to launch Command Prompt in Recovery mode like you do in Fix 1. And execute the command “chkdsk c: /f”. This command will check the C drive and fix found errors.

▶ Solution 4. Check the system files integrity

Besides checking the system partition for errors, you can also make use of SFC (System File Checker) tool to scan for and restore corruptions in Windows system files. It will scan all protected system files, and replace corrupted files with a cached copy.

For this task, you just need to run “sfc/scannow” command in the Command Prompt window.

▶ Solution 5. Repair damaged MBR/BCD

MBR and BCD are quite important for booting Server successfully. So when your Server 2016 cannot boot as usual, you can try to repair them. There are two methods available.

A. Repair MBR/BCD through Command Prompt

Step 1. Access the “Command Prompt” window in the recovery mode.

Step 2. Type the below commands and press “Enter” after each one.

● bootrec/fixmbr

● bootrec/rebuildbcd

B. Rebuild MBR via third-party partition software

If you don’t have Server 2016 installation DVD or CD and cannot access to Server recovery environment, you can use AOMEI Partition Assistant Server. It can help you create a bootable USB flash drive without requiring the installation DVD or CD. Besides, it comes with the user-friendly interface, easy to follow and operation for either experts or newbies. With it, you can effortlessly rebuild corrupted MBR by 3 steps in all Server 2025/2022/2019/2016/2012. Here are specific steps.

Step 1. Connect an empty USB flash drive to a working Server computer, install and launch AOMEI Partition Assistant Server on that computer, too.

Step 2. Click “Tools” in the top toolbar, and choose “Make Bootable Media”.

Step 3. Choose “USB Boot Device” and select the prepared USB flash drive. Click “Proceed” then.

Step 4. Wait for the process to finish.

Note: the bootable USB flash drive contains the pre-installed AOMEI Partition Assistant Server.

Step 5. Then connect the just created bootable media into the Server 2016 computer, which cannot boot due to “Inaccessible Boot Device”. Change boot sequence in BIOS to boot computer from it.

Step 6. Once login, you will see AOMEI Partition Assistant Server running. Then right click the system disk and select “Rebuild MBR”.

Step 7. Choose a proper MBR type for your current Server operating system and click “OK”.

Step 8. Then click “Apply” to commit the pending operation.

You can also use AOMEI Partition Assistant Server to:

⇒Check Server 2016 partition for errors and fix them via the “Check Partition” function.

⇒Scan the entire Server 2016 hard disk to check whether there are some errors by the “Surface Test” feature, which is also a great  method for Windows Server 2016 inaccessible boot device repair.

⇒If any data loss happens during your operation, you can use the "Recover Data" function to retrieve lost data.

Final Words

In this post, we have introduced 5 different Server 2016 inaccessible boot device fixes. I hope that you can get your Windows Server 2016 boot up successfully. Worth to mention, rebuilding MBR via AOMEI Partition Assistant Server can also help repair “Inaccessible Boot Device” in other Server operating systems like Server 2003/2008/2012/2019/2022/2025. Besides, the AOMEI Partition Assistant Unlimited allows installing the program on unlimited computers within one company.  The Unlimited Edition has a worth-trying function, "Create Portable Version", enabling you to create AOMEI Partition Assistant to a removable device.