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claudetools/.claude/memory/windows-offline-dism-repair-gotchas.md
Howard Enos cd806da576 sync: auto-sync from HOWARD-HOME at 2026-06-23 15:28:30
Author: Howard Enos
Machine: HOWARD-HOME
Timestamp: 2026-06-23 15:28:30
2026-06-23 15:29:01 -07:00

3.1 KiB

name: windows-offline-dism-repair-gotchas description: Windows won't-boot / offline DISM repair playbook — diagnose wedged-update boot loops, and the WinPE source/mount gotchas (wim: not allowed offline, Ventoy breaks WIM mount) metadata: type: reference

Field-learned gotchas for repairing a Windows box that won't boot, from offline WinPE/recovery. First hit on Four Paws AvImark server (Syncro #32447, 2026-06-23) — boot-looping into Automatic Repair.

1. Diagnose the REAL boot blocker before chasing DISM corruption. A machine that drops into Automatic Repair is failing on something boot-critical (disk, registry hive, boot files, or a wedged update) — NOT on shell/Search/appx component-store corruption. Component-store corruption in ShellExperienceHost/StartMenuExperienceHost/windowssearchengine/Cortana is a symptom, not the cause; repairing it does NOT fix the boot loop. Read the actual cause first: C:\Windows\System32\LogFiles\Srt\SrtTrail.txt, and run chkdsk C: /f (disk errors are the #1 Automatic Repair cause).

2. FaultyPackageInProgress + hundreds of "Install/Uninstall Pending" packages = a wedged cumulative-update transaction. That IS the boot blocker. Confirm offline with dism /Image:C:\ /Get-Packages /Format:Table — look for many Install Pending / Uninstall Pending lines at the same timestamp (a half-applied CU swapping old build -> new build). Try to back it out with dism /Image:C:\ /Cleanup-Image /RevertPendingActions, or WinRE -> Troubleshoot -> Advanced -> Uninstall Updates -> "Uninstall latest quality update". If RevertPendingActions FAILS and there's no pending.xml, the transaction is too corrupt to repair in place -> clean install.

3. Offline DISM won't accept a wim: source (0x800f082e CBS_E_NOT_ALLOWED_OFFLINE). For /Image:C:\ /Cleanup-Image /RestoreHealth you must mount the install.wim and point /Source at the mounted folder's \Windows, not use /Source:WIM:...:idx:

mkdir C:\wimmount
dism /Mount-Image /ImageFile:D:\sources\install.wim /Index:6 /MountDir:C:\wimmount /ReadOnly
dism /Image:C:\ /Cleanup-Image /RestoreHealth /Source:C:\wimmount\Windows /LimitAccess /ScratchDir:G:\scratch
dism /Unmount-Image /MountDir:C:\wimmount /Discard

Mount point must be an empty folder on a writable NTFS local drive (not the USB — Rufus UEFI sticks are FAT32 and hold the source itself). 0x800f0915 (repair content missing) usually means the offline backup store is gone and /LimitAccess blocked the WU fallback.

4. Ventoy breaks WIM mounting (0xc1420134 / "GetMountedImagesKey... file not found"). Ventoy serves the ISO through a virtual driver that also blocks wim: source access. Use a Rufus-built install stick instead — mounting then works.

5. Build matters for the source: Win11 25H2 (build 26200) is 24H2 (build 26100) + enablement package; component store is 26100-versioned. DISM matches on component version, not the marketing build, so the matching media for a 26200 box is a 24H2 / 26100 ISO. Verify before repairing: dism /Get-WimInfo /WimFile:<wim> /Index:6.

Related: cyndyoffice-physical-hp-lockups, feedback_rmm_system_context_mapped_drives.