reg delete fails for ContentDeliveryManager\Subscriptions on 25H2 June 2026 ISO (key absent in default user hive)

[HaleTom]

Summary

Remove-RegistryValue emits a NativeCommandError when the target registry key does not exist in the mounted image's default user hive. On the Windows 11 25H2 (June 2026) consumer ISO, the Subscriptions subkey under ContentDeliveryManager is absent, so reg delete fails with "The system was unable to find the specified registry key or value."

Environment

• ISO: en-us_windows_11_consumer_editions_version_25h2_updated_june_2026_x64_dvd_2045a41c.iso
• Script: tiny11maker.ps1 (release 09-07-25, current main)
• OS: Windows 11 (build host)

Error output

Set registry value: HKLM\zNTUSER\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager\SystemPaneSuggestionsEnabled
Set registry value: HKLM\zSOFTWARE\Policies\Microsoft\PushToInstall\DisablePushToInstall
Set registry value: HKLM\zSOFTWARE\Policies\Microsoft\MRT\DontOfferThroughWUAU
Removed registry value: HKLM\zNTUSER\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager\Subscriptions
reg.exe : ERROR: The system was unable to find the specified registry key or value.
At C:\tmp\tiny11\tiny11maker.ps1:63 char:3
+         & 'reg' 'delete' $path '/f' | Out-Null
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (ERROR: The syst...y key or value.:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

Removed registry value: HKLM\zNTUSER\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager\SuggestedApps
Set registry value: HKLM\zSOFTWARE\Policies\Microsoft\Windows\CloudContent\DisableConsumerAccountStateContent

Root cause

The Remove-RegistryValue function (lines ~58-67) wraps reg delete in a try/catch and pipes to Out-Null:

function Remove-RegistryValue {
    param ( [string]$path )
    try {
        & 'reg' 'delete' $path '/f' | Out-Null
        Write-Output "Removed registry value: $path"
    } catch {
        Write-Output "Error removing registry value: $_"
    }
}

Two problems:

1. Out-Null does not suppress native-command stderr in PowerShell 5.1. When reg.exe writes "ERROR: ..." to stderr, PowerShell surfaces it as a NativeCommandError record regardless of the | Out-Null pipe, and the try/catch does not reliably catch native-command stderr streams (the error record is written to the error stream before the catch block engages, depending on $ErrorActionPreference).
2. The Subscriptions key is genuinely absent in the 25H2 June 2026 image's Users\Default\ntuser.dat. This is expected — Microsoft has been progressively trimming the ContentDeliveryManager subtree across builds. The script should treat "key not found" as a non-fatal condition rather than surfacing it as an error.

Note the output also shows Removed registry value: ...Subscriptions before the error — the success Write-Output fires because reg delete's exit code path and stderr handling race the catch block.

Suggested fix

Check for the key's existence before deleting, and/or redirect stderr explicitly:

function Remove-RegistryValue {
    param ( [string]$path )
    if (-not (reg query $path 2>$null)) {
        Write-Output "Skipped (not present): $path"
        return
    }
    & 'reg' 'delete' $path '/f' 2>$null | Out-Null
    if ($LASTEXITCODE -eq 0) {
        Write-Output "Removed registry value: $path"
    } else {
        Write-Output "Skipped (exit $LASTEXITCODE): $path"
    }
}

This makes absence non-fatal and removes the noisy NativeCommandError stack trace from the build log. The same hardening would apply to the other Remove-RegistryValue calls (e.g. the Edge uninstall keys, UScheduler_Oobe\OutlookUpdate, DevHomeUpdate) which may also be absent on future builds.

Impact

Non-fatal — the build completes and the resulting image is usable. The issue is cosmetic/log noise plus a misleading error message suggesting something failed when the key simply never existed. Worth fixing so users running the June 2026 25H2 ISO don't file duplicate reports.

Workaround

None needed — the error is benign. Users can ignore it.