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Fix Windows Server Boot Failure After Windows Update


This guide explainswalks howthrough to recoverrecovering a Windows Server system that fails to boot after a Windows Update. The processIt uses Windows Recovery Environment (WinRE) and DISM to revert or remove problematic updates.

This

Tested tutorial applies towith Windows Server 20192019. butThe process is similarnearly identical for Server 2016 / 2022.

Prerequisites

  • Windows Server installation ISO matching your OS version
  • Physical console, iDRAC, iLO, or other versions.

    remote KVM access
  • Administrator credentials
  • BitLocker recovery key (if BitLocker is enabled)

Step 1 — ObtainBoot into Windows InstallationRecovery MediaEnvironment

  1. Download the correct Windows Server ISO matchingfrom yourMicrosoft. OS version.
    Search for:Search: "Windows Server 2019 Evaluation"Evaluation ISO"
  2. Download the ISO from Microsoft's official website.
  3. Create bootable media:
    • Write ISO to USB
    • OR mount ISO via iDRAC Virtual Media
  4. Boot the server fromusing:
    • Bootable USB
    • Virtual Media via iDRAC / iLO
  5. At the installationinstaller media.screen:
    • Click Next
    • Select Repair your computer
  6. Navigate to:
    • Troubleshoot → Advanced Options → Command Prompt

Note: If theWindows serveralready entered aautomatic recovery loopafter aftermultiple failed boots, ityou may automaticallysee showthis the recovery screenmenu without external media.

Step 2 — EnterUnlock WindowsBitLocker Recovery(If EnvironmentEnabled)

    If

  1. Bootthe tosystem installationdrive media
    2. is
  2. Selectencrypted, Next
    3. unlock
  3. Clickit Repairfirst:

    your
    manage-bde computer
    4. -status
  4. Select:manage-bde
      -unlock
    • Troubleshoot
      • D:
    • Command-RecoveryPassword Prompt
      • YOUR-KEY-HERE

    Replace

    5. drive
letter and recovery key as needed.

Step 3 — Identify the Windows Installation Drive Letter

In recovery mode, thedrive systemletters change. The OS drive mayis notoften beNOT C:.

You
diskpart
mustlist locatevolume
exit

Note the volume containing the Windows installation manually.folder.

dir C:
dir D:
dir E:

Look for a folder named Windows. Whichever drive contains it is your OS drive.

Example: Windows foundlocated on D:\

Step 4 — Check Disk Integrity (Recommended)

Before touching updates, verify filesystem health:

chkdsk D: /f

Replace D: with your OS drive.

Step 5 — Revert Pending Windows Updates

RunThis DISM to cancelcancels unfinished update operations:operations.

dism /image:D:\ /cleanup-image /revertpendingactions

Replace D:\ with your actual Windows drive.

This process may take several minutes if updates were pending.minutes.

When complete:

  1. Close Command Prompt
  2. Click Continue → Boot to Windows

If Windows boots successfully, stop here.

Step 6 — Remove a Fully Installed Broken Update

If Windows crashes after login or loops during boot, the update must be manually removed.

List Installed Packages

dism /image:D:\ /get-packages

Recent updates appear near the bottom.

Remove a Package

dism /image:D:\ /remove-package /packagename:PACKAGE_NAME

Tip: Highlight package → right-click to copy → right-click to paste.

Remove updates one at a time and reboot between attempts.

Step 7 — Repair Boot Configuration (If System Still Won’t Start)

If the system fails before Windows loads, repair the bootloader:

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

If /fixboot returns Access Denied:

bootsect /nt60 sys

Step 8 — Run System File Check Offline

Scan for corrupted Windows files:

sfc /scannow /offbootdir=D:\ /offwindir=D:\Windows

Step 9 — Final Reboot

  1. Exit Command Prompt
  2. Remove installation media
  3. Reboot normally

Troubleshooting Notes

  • If DISM fails: verify correct drive letter
  • If drive is read-only: run diskpart → attributes disk clear readonly
  • If BitLocker relocks: unlock again
  • If updates reinstall automatically: pause Windows Update after recovery

Summary

  • Boot to recovery
  • Unlock BitLocker
  • Locate OS drive
  • Check disk health
  • Revert pending updates
  • Remove broken packages
  • Repair bootloader if needed
  • Run SFC

This procedure resolves most Windows Update boot failures without reinstalling the operating system.

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