Confirm-SecureBootUEFI: Document missing info on error "Variable is currently undefined: 0xC0000100" when Secure Boot is disabled

[Whisley-Wang]

Prerequisites

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Links

• https://github.com/MicrosoftDocs/windows-powershell-docs/blob/main/docset/winserver2025-ps/SecureBoot/Confirm-SecureBootUEFI.md
• https://learn.microsoft.com/en-us/powershell/module/secureboot/confirm-securebootuefi?view=windowsserver2025-ps

Summary

When running Confirm-SecureBootUEFI on a physical machine with Secure Boot manually disabled (UEFI system, not a VM, running PowerShell as Administrator), the following error is shown:

Exception getting Secure Boot information:
Powershell error: Confirm-SecureBootUEFI : Variable is currently undefined: 0xC0000100
At line:1 char:1

• Confirm-SecureBootUEFI

•   + CategoryInfo          : ResourceUnavailable: (Microsoft.Secur...BootUefiCommand:ConfirmSecureBootUefiCommand) [C 
   onfirm-SecureBootUEFI], StatusException
    + FullyQualifiedErrorId : GetFWVarFailed,Microsoft.SecureBoot.Commands.ConfirmSecureBootUefiCommand
  
  
  
  

Details

The current official documentation does not mention this error or what it means. After investigation, it appears that some UEFI firmware implementations remove Secure Boot variables entirely when Secure Boot is disabled, causing this error to appear instead of simply returning $False.

Suggested Fix

Please update the documentation for Confirm-SecureBootUEFI to explain that this error may occur when Secure Boot is disabled, depending on the UEFI firmware, and that it does not necessarily indicate a problem with PowerShell or Windows.