🟠 High   ⏱ 5–30 min  Last verified: 29 May 2026
Affected versions: Windows Server 2016

📖 ~1 min read

Table of contents
  1. Symptom & Impact
  2. Environment & Reproduction
  3. Root Cause Analysis
  4. Quick Triage
  5. Step-by-Step Diagnosis
  6. Solution — Primary Fix
  7. Solution — Alternative Approaches
  8. Verification & Acceptance Criteria
  9. Rollback Plan
  10. Prevention & Hardening
  11. Related Errors & Cross-Refs
  12. References & Further Reading

Symptom & Impact

Server fails during early startup with a winload.efi error and cannot start business workloads.

Environment & Reproduction

Usually observed after failed updates or damaged EFI partition files.

dir S:EFIMicrosoftBoot
dir C:WindowsSystem32winload.efi

Root Cause Analysis

The EFI boot loader path in BCD is incorrect or the winload file is corrupted.

Quick Triage

Confirm partition letters and verify EFI volume is mounted correctly.

diskpart
list vol
sel vol 
assign letter=S

Step-by-Step Diagnosis

Inspect boot manager entries and file integrity from recovery shell.

bcdedit /enum
sfc /scannow /offbootdir=C: /offwindir=C:Windows
Illustrative mockup for windows-server-2016 — terminal_or_powershell
Winload error diagnostics — Illustrative mockup — Progressive Robot

Solution — Primary Fix

Recreate EFI boot files and re-register boot manager entries.

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bcdboot C:Windows /s S: /f UEFI
bootrec /rebuildbcd
Illustrative mockup for windows-server-2016 — error_dialog
Boot file restore workflow — Illustrative mockup — Progressive Robot

Solution — Alternative Approaches

Restore the EFI partition from backup when file reconstruction is incomplete.

wbadmin start recovery -itemType:Volume -items:S:

Verification & Acceptance Criteria

Boot sequence passes loader stage and reaches Windows login without recovery prompts.

bcdedit /enum | findstr /i winload

Rollback Plan

Rollback to pre-update snapshot if post-fix kernel startup remains unstable.

dism /image:C: /cleanup-image /revertpendingactions

Prevention & Hardening

Validate update health and monitor EFI partition health during maintenance windows.

Get-Volume | Select DriveLetter,FileSystemLabel,HealthStatus

Related: 0xc000000f, missing operating system, and BCD object not found.

Related tutorial: View the step-by-step tutorial for Windows Server 2016.

View all Windows Server 2016 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Microsoft Learn recovery options for UEFI boot failures in Windows Server environments.

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