updated LKGC script v1.3

[Tony Mocanu (anmocanu)]

This script enables Last Known Good Configuration (LKGC) by incrementing registry values for recovery from boot issues. It includes enhancements for logging and error handling, ensuring proper execution and tracking of applied changes. This update enhances the win-LKGC.ps1 script to increment Last Known Good Configuration (LKGC) registry values, log changes, and ensure proper handling of nested VMs. It includes improved error handling, logging, and a new mechanism to track whether LKGC was applied on any disk. .VERSION
v1.3: [May 2026] - Updated the script (current)
- Added LKGC_APPLIED log flag (per disk + overall) and corrected final summary message.
- Fixed Get-VM crash when Hyper-V module is not installed on host (guarded Get-VM).
- Fixed false "already set" detection by requiring ALL thresholds (AND instead of OR).
v1.1: Previous version
v0.1: Initial commit

[EdwinBernal1]

Issues Found

🟢 Minor: OS version parsing is heuristic-based

The script derives $winosver from first numeric token in ProductName. This is pragmatic but brittle if naming format changes.

Recommendation: consider reading a stable version key (e.g., CurrentMajorVersionNumber / CurrentBuild) when available.

[EdwinBernal1]

Tony Mocanu (@anmocanu) could you help us with the review of these findings

Findings

Critical

File	Context	Issue	Recommendation
—	—	None	—

Warning

File	Context	Issue	Recommendation
win-LKGC.ps1	version number	PR title says v1.3, but the top .VERSION entry in the file is v1.4 ("Production hardening").	Reconcile the version in the title/history so it is unambiguous.
win-LKGC.ps1	Log-* wrapper	Logging-wrapper pattern duplicated across the batch.	Extract shared helper.

Info

File	Context	Suggestion
win-LKGC.ps1	backup + rollback	SYSTEM hive backup with restore-on-failure is the strongest safety pattern in the batch. Good.
win-LKGC.ps1	AND-logic fix	The OR→AND change is a genuine bug fix; verify the version-specific thresholds (Win10/2016+ vs 2012) match intended LKGC semantics.
win-LKGC.ps1	unload retry	Pre-load defensive reg unload, plus 3× unload retry with GC — reduces stuck-hive risk on detach.

Operational Risk Assessment

Factor	Rating	Notes
Scope	Low-Medium	Single script; registry hive load/modify/unload.
Destructive ops	Low-Medium	Registry Select edits — but backed up and rolled back on failure.
Rollback possible	Yes	Per-disk SYSTEM hive backup + automatic restore on failure.
Testing documented	Unknown	Confirm test evidence in the PR.
Gen compatibility	Gen1+Gen2	Operates on the lettered Windows volume; generation-agnostic.

[Gabriela Limoli (glimoli)]

✅ VMRepair Validated — win-LKGC.ps1 v1.3

Tested by: VMRepairMint Script Testing Framework
Test Date: 2026-08-07
Breaker: break-win-LKGC-v3.ps1 (offline SYSTEM hive on attached copy disk)
Validation: CHANGES_APPLIED=TRUE marker in repair script output

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Test Results — 6/6 VMs FIXED (100%)

Configuration	OS	Gen	Fault Injected	After-State	Result
Modern Standard	Win2022	Gen2	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS
Legacy Support	Win2022	Gen1	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS
Encrypted Modern	Win2019	Gen2	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS
Cost-Optimized	Win2022	Gen2	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS
Latest Gen2 + Premium	Win2022	Gen2	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS
Mid-Tier 2016	Win2016	Gen2	✅ [BREAKER-SUCCESS]	✅ FIXED	✅ PASS

Scores

Metric	Score	Status
Code Quality	96/100	✅ A+
Execution Success	100%	✅
Header Documentation	37/100	❌ Missing .DESCRIPTION / .NOTES
Telemetry Coverage	0%	❌ No Log-Start / Log-Success events

Improvements Recommended

1. ❌ Header Documentation (37/100)

.DESCRIPTION and .NOTES blocks are missing. These are required by the VMRepair script standard and needed for automated documentation generation.

2. ❌ Telemetry Coverage (0%)

No Log-Start, Log-Success, or Log-Error events. Without telemetry, production failures are invisible in Application Insights.

Log-Start -Message "Starting LKGC restoration" -Properties @{
    SelectBefore = "$($before.Current),$($before.Default),$($before.Failed),$($before.LastKnownGood)"
}
Log-Output "LKGC APPLIED" -Properties @{
    SelectAfter = "$($after.Current),$($after.Default),$($after.Failed),$($after.LastKnownGood)"
}

3. ℹ️ Minor — Trailing Whitespace (PSScriptAnalyzer)

Lines 6, 8, 10, 11. Not blocking.

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🔗 SME Work Item: Tooling 59898 win-LKGC
Generated by VMRepairMint Script Testing Framework