Windows 10: Can executing "bootrec /RebuildBCD" make a booting PC to not boot?

Hello,

I have an issue executing the Defender Offline Scan. If I try to execute it via the PowerShell I get the following error:

Windows PowerShell
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PS C:\Users\XXX> Start-MpWDOScan
Start-MpWDOScan : Errors were encountered when attempted to run WDO scan on your PC.
At line:1 char:1
+ Start-MpWDOScan
+ ~~~~~~~~~~~~~~~
+ CategoryInfo : PermissionDenied: (MSFT_MpWDOScan:ROOT\Microsoft\...\MSFT_MpWDOScan) [Start-MpWDOScan],
CimException
+ FullyQualifiedErrorId : HRESULT 0x80070005,Start-MpWDOScan

And when I execute it from the Windows Security scan options, my computer reboots giving the following blue screen error:

Recovery
Your PC/Device needs to be repaired
The application or operating system couldn't be loaded because a required file is missing or contains errors.

File: \windows\system32\winload.efi
Error code: 0xc0000225

You'll need to use recovery tools. If you don't have any installation media (like a disc or USB device), contact your PC administrator or PC/Device manufacturer.

Press Enter to try again
Press F1 to enter Recovery Environment
Press F8 for Startup Settings
Press Esc for UEFI Firmware Settings

I have no idea what the error from the PowerShell indicates, but for the winload.efi error, I have read in other threads that the best way to proceed is to rebuild the BCD and MBR using the USB recovery device from the manufacturer. However, my computer boots fine and I do not want to induce an additional error by modifying the BCD or MBR.

So my central question is, does the possibility exist that I mess up my correct boot by rebuilding the BCD and MBR from the USB recovery device? Also, it would also help if somebody could interpret what is the cause of the error I find in the PowerShell when manually running the Defender Offline Scan?

I am running Windows 10 Pro Version 20H2 (OS Build 19042.685) Windows Feature Experience Pack 120.2212.551.0 on a Sager workstation.

:)

 

Windows 10 Boot

In the bootrec.jpg image:

Rebuildbcd found 1 copy outside of the windows store.

Total identified Windows installations: 1

Repeat the steps in the image:

bootrec /fixmbr

bootrec /fixboot

bootrec /scanos

bootrec /rebuildbcd

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

type: Y

then enter key

It should display :

The operation completed successfully. (The BCD rebuild is complete.)

reboot

It it works that will complete the troubleshooting.

If it fails then it may be able to be rebuilt with additional steps.

 

Windows 10 cannot boot. Cannot run bootrec /rebuildbcd

Bootrec is only in the recovery options so you may not be where it is available.

The rebuildbcd command will show 0 if there are no Windows 10 installs OTHER than the one already in the System Partition, so that is normal.

Do the bcdedit command and copy and past the listing.

It should be able to boot..but it should not have the letter B if it still does. If it does and you need to get rid of it, select the B volume and use diskpart , then after selecting the volume..

remove letter=b

 

Windows Installation Error (Unable to update boot configuration)

Hello,

I have the exact same issue that detailed in this question. I have completed your suggested CMD commands:

• 
  bootrec /fixmbr
  
• 
  bootrec /fixboot
  
• 
  bootrec /scanos
  
• 
  bootrec /rebuildbcd
  

But I think you left off the last part. After "bootrec /rebuildbcd, Windows asks : "Add installation to boot list? Yes(Y)/No(N)/All(A)"

Which do I choose??? Y, N, or A??

Eagerly awaiting your reply. Thanks!

•