Repair Windows Server 2016 “BootMgr is Missing” Boot Error

If your Windows Server 2016 is broken, you may need to repair its boot record. Here are 3 methods to fix Server 2016 boot errors.

Step 1: Boot to Recovery Mode

The 2 options discussed in this guide require you to boot your server to recovery. For each method, I will refer you to this link – Boot to Windows Server 2016 Recovery Mode Without Installation Media (DVD or USB).

Use the steps described in the link above until you get to the Choose an option screen shown below. Then proceed with the remaining steps in each method.

Step 2 (Option 1): Rebuild the Boot Configuration Data (BCD)

The first option for Windows Server 2016 Repair Boot is to rebuild the BCD.

Here are the steps:

• Boot to Windows Server 2016 Recovery Mode. When you get to Choose an option, click Troubleshoot.

• At Advanced options, click Command Prompt.

• To open Command Prompt, choose an account with admin privilege. In this example, I will click Administrator.

• Finally, type the password for the account. Then click Continue. Command Prompt will open.

In the next steps you will run some commands that will repair your server’s Boot Configuration Data (BCD). This commands will fix corrupt boot configuration data.

There are two sets of command options below: 1, commands to use if your computer has BIOS with MBR systems. 2, commands applicable to UEFI systems

Commands to Repair Boot (Rebuild BootMgr) for MBR Systems

If your computer uses MBR, follow the steps below to repair Server 2016 boot records:

• At the previous command prompt, enter the following commands one at a time. Then press enter at each command.

bcdedit /export C:\BCD_Backup

attrib c:\\boot\\bcd -h -r –s 

ren c:\boot\bcd bcd.old

bootrec /rebuildbcd  

When the last command completes, you will receive this prompt:

Add installation to boot list? Yes/No/All:

Type A and press enter.

Steps to Repair Server 2016 Boot for UEFI systems

If your Server runs the new UEFI use the steps here for Windows Server 2016 repair boot:

This section has two parts: part 1, use diskpart to assign a drive letter to the EFI volume. part 2, rebuild BCD.

Here are the steps:

• At the command prompt type the command below. Then press enter

DISKPART

The last command will open dsiakpart command prompt.

• At the DISKPART prompt, type this commend and press enter

LIST DISK

All available disks on your Server will be displayed.

• Next, to select the disk with your Windows Server 2016 installation use the command below:

 SELECT DISK 0 

• To display available volumes in the selected disk, type the command below. Then press enter.

LIST VOLUME

Before you proceed to the next step, you need to identify the EFI volume

Here is how you identify the EFI volume:

1. It should be formatted with FAT32
2. Size is likely to be about 100mb (shown as 99mb in this example)
3. The volume may likely show as hidden

To select the EFI volume, run a command similar to this command:

SELECT VOLUME 3

Replace 3 with the # for your EFI volume

• Finally for this part, assign the volume a drive letter with this command:

 ASSIGN LETTER K:

When you run the last command, you should receive “DiskPart successfully assigned the drive letter or mount point”. If you receive any other message, repeat the last command with a different drive letter.

• To exit DISKPART, use exit command.

EXIT

You will be returned to Command Prompt. DO NOT close it as you will need it in part 2 of this section.

Here is the second part for Windows Server 2016 repair boot (Repair BCD):

• At the command prompt, change directory to point to the EFI boot drive. Use the command below:

 CD /d k:\efi\microsoft\boot\ 

K: is the drive letter you assigned the EFI volume. See the result of the command below:

• Finally, execute the following commands one at a time:

bcdedit /export K:\efi\microsoft\BCD_Backup 

The command creates a backup of the boot configuration data (BCD). Just in case you need to restore it!

ren bcd bcd.old 

It renames the current BCD to bcd.old. Finally, to rebuild BCD and repair Windows Server 2016 boot, use this command:

bootrec /rebuildbcd 

The last command will take a short while to complete, then it will return prompt for confirmation –

Add installation to boot list? Yes/No/All:

Type A and press Enter.

• Exit command prompt. Then click Turn off your PC.

From my experience, the fix you just went through will repair Windows Server 2016 boot.

But if in the rare instance that your server still cannot boot, try the next fix…

Step 2 (Option 2): Restore to a Previous System Restore Point

Here are the steps for this fix:

• Boot to Windows Server 2016 Recovery Mode. When you get to Choose an option, click Troubleshoot.

• At Advanced options, select System Image Recovery. Then follow the wizard to revert your server to a previous restore point.

Frequently Asked Questions

Conclusion

The first fix in this guide is likely to resolve Windows Server 2016 boot problems. But if it doesn’t and you have a restore point you may try the second method.

I am confident that one of the methods will get your server up and running.

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