Update sac-enabler.ps1 to v1.3

[anmocanu]

This script enables Special Administration Console (SAC) and Serial Console boot settings on an attached OS disk's BCD store. It includes enhanced logic for Gen2 disks and improved error handling.
.VERSION
v1.3: [May 2026] - Updated the script again (current)
- Fixed breaking exception when the Hyper-V module is not installed on the host.
- Added explicit checking via Get-Module before executing nested VM discovery.
v1.2: [May 2026] - Updated the script
- Included advanced Gen2 unlettered EFI fallback and dynamic drive-letter assignment.
v0.1: Initial commit. This was the version 1.0 of the script

[EdwinBernal1]

Issues Found

🟡 Potential compatibility gap: only checks winload.exe for OS detection

The script sets $isOsPath via \windows\system32\winload.exe only. Some UEFI-oriented scenarios rely on winload.efi path detection. If winload.exe is absent or not suitable in edge images, OS detection may fail even if the disk is valid.

Recommendation: mirror the pattern used in PR #130 and check both winload.exe and winload.efi.

🟢 Minor: fallback failure path could be clearer

If no default boot entry is parsed from displayorder, the script exits with generic failure state. Add explicit warning when $defaultLine/GUID extraction fails for easier troubleshooting.

[EdwinBernal1]

@anmocanu could you help us with the review of these findings

Findings

Critical

File	Context	Issue	Recommendation
—	—	None	—

Warning

File	Context	Issue	Recommendation
sac-enabler.ps1	temp EFI letter	diskpart assigns a temporary drive letter to the EFI partition. Cleanup is in finally (good), but a hard process kill between assign and cleanup could leave an orphaned mount on the rescue host.	Acceptable; the finally guard is the right mitigation. Optionally add a startup sweep for stale temp letters.
sac-enabler.ps1	logging	Desktop-only log, not the plugin dir auto-collected by az vm repair run.	Dual-write for auto-collection (batch-level).
sac-enabler.ps1	Log-* wrapper	Duplicated logging-wrapper pattern (see batch note).	Extract shared helper.

Info

File	Context	Suggestion
sac-enabler.ps1	v2 helper + EFI	Because Get-Disk-Partitions-v2 does not letter EFI partitions, the added diskpart logic is the correct compensation. Good Gen1+Gen2 coverage.
sac-enabler.ps1	paired diskpart	assign/remove letter operations are paired across try/finally — good registry/partition hygiene.

Operational Risk Assessment

Factor	Rating	Notes
Scope	Low-Medium	Single script; adds diskpart partition manipulation.
Destructive ops	Low	BCD /set edits are reversible via bcdedit; temp letter add/remove only; no file/registry deletion.
Rollback possible	Yes	SAC/EMS settings can be reverted with bcdedit; .VERIFICATION documents checks.
Testing documented	Yes (guide)	.SCENARIO_RECREATION/.VERIFICATION provide a repro/validation path.
Gen compatibility	Gen1+Gen2	Explicit Gen2 unlettered-EFI handling.