Windows Update error 0x800F081F: repair Windows and retry the update

Windows Update or DISM can fail with 0x800F081F, whose servicing name is CBS_E_SOURCE_MISSING. In plain language, the component-servicing operation could not locate a required package or file source. The code can appear while installing a cumulative update, while DISM tries to repair the component store, or while enabling an optional feature. Those are related servicing contexts but not identical repair cases.

This article covers a normally booting Windows 10/11 installation whose Windows Update repeatedly fails with 0x800F081F. It first records the exact KB/build and component-store evidence, performs Microsoft's bounded DISM/SFC repair sequence, and then uses a repair reinstall when the source problem persists. Windows 11 can use Fix problems using Windows Update when that feature is available; Windows 10 or an ineligible Windows 11 system can use an in-place repair install from matching official media.

Searchable Windows error codes and exact messages

Related codes such as 0x800F0906, 0x800F0907, 0x800F0831, and 0x80073712 are not aliases for 0x800F081F. Record and route them separately unless the same attempt also shows CBS_E_SOURCE_MISSING.

Use this procedure when:

• Windows 10 or Windows 11 starts and remains stable enough to complete a backup and repair installation;
• Windows Update identifies a specific quality, security, cumulative, or feature update that repeatedly fails with 0x800F081F;
• a full restart and one controlled retry produce the same code;
• the system drive and component-store logs are readable;
• no known release-health hold or superseding update already explains the exact KB/build; and
• sufficient free space, stable power, and a verified backup are available for a repair reinstall if DISM/SFC do not resolve the failure.

The repair-reinstall branch is especially appropriate when /RestoreHealth itself returns 0x800F081F, or when the exact update still fails after DISM completes successfully and SFC completes.

Do not use this article when Windows cannot start, the disk is unstable, the Windows installation is not the correct one, or the error occurs only while enabling .NET Framework 3.5 or another optional feature that has a documented feature-source/policy procedure.

It also does not apply when:

• the only visible code is different from 0x800F081F;
• Setup fails in a boot/upgrade phase with a 0xC1900101, 0xC1900107, 0xC1900208, or another setup-specific code;
• Windows Update is disabled by policy or reports 0x80070422/ERROR_SERVICE_DISABLED;
• the target update is withdrawn, blocked by a safeguard hold, or replaced by a later cumulative update;
• the system is an enterprise-managed image whose servicing source is controlled by WSUS, Configuration Manager, Group Policy, or another administrator; or
• Keep personal files and apps is unavailable in the in-place Setup path.

Do not use the repair-reinstall feature to bypass an organizational servicing policy.

The exact package/file missing from the component store and the event that removed or mismatched it may remain unknown. A detailed CBS package-chain analysis is not required before a supported repair reinstall.

The following may not remain unknown:

• the exact failing update title and KB number, when one is shown;
• the complete displayed code and message;
• the installed Windows edition, display language, architecture, version, and OS build before an ISO-based repair;
• whether DISM and SFC completed, failed, or reported corruption;
• whether Fix problems using Windows Update is present and permitted;
• whether the PC is managed by work/school; and
• whether Setup's final confirmation explicitly says Keep personal files and apps.

• Local administrator access
• A verified backup of important personal files and any application-specific data
• Stable AC power; a laptop should remain connected to its charger
• A reliable Internet connection for Windows Update repair reinstall
• Adequate free space on the Windows system drive for the repair download, temporary files, and rollback data
• The exact failed update name/code recorded
• For the ISO branch, official Microsoft installation media matching the installed architecture, edition, system/default UI or install language, and intended Windows feature release, with a build/repair level not older than the installed OS—not merely media that happens to enable Keep personal files and apps
• Product/application installation information for software that is operationally critical

A restore point is useful when available but is not a substitute for a file backup or system image.

1. Open Settings > Windows Update > Update history and record the failed update's complete title, KB number, date, and 0x800F081F message.

2. Restart Windows. Return to Windows Update and retry the same update once. If it succeeds, stop; no repair reinstall is needed.

3. If the same code returns, pause repeated retries. Record the installed version:

   winver
   

4. Open an elevated Command Prompt and create an evidence folder:

   md "%USERPROFILE%\Desktop\WU-0x800F081F"
   systeminfo > "%USERPROFILE%\Desktop\WU-0x800F081F\systeminfo-before.txt"
   dism /Online /Get-CurrentEdition > "%USERPROFILE%\Desktop\WU-0x800F081F\edition-before.txt"
   fsutil volume diskfree %SystemDrive% > "%USERPROFILE%\Desktop\WU-0x800F081F\diskfree-before.txt"
   

5. Copy the readable servicing logs before running a repair. Locked or rotated files may not all copy; record each result:

   copy "%SystemRoot%\Logs\CBS\CBS.log" "%USERPROFILE%\Desktop\WU-0x800F081F\CBS-before.log"
   copy "%SystemRoot%\Logs\DISM\dism.log" "%USERPROFILE%\Desktop\WU-0x800F081F\DISM-before.log"
   

6. Search the current CBS log for the code and servicing name:

   findstr /i /c:"0x800f081f" /c:"CBS_E_SOURCE_MISSING" "%SystemRoot%\Logs\CBS\CBS.log" > "%USERPROFILE%\Desktop\WU-0x800F081F\CBS-081f-lines.txt"
   

7. Disconnect nonessential external storage, docks, printers, and specialty USB devices before a repair reinstall. Keep input devices, display, network, and the backup destination only as required.

8. Close applications and confirm no other installer or Windows Update restart is pending.

1. Confirm that the Windows Update failure—not a search result—actually displays 0x800F081F.

2. Verify that the target update is still applicable and not already installed or superseded. Search Update history for its KB. If Windows Update now offers a later cumulative update, install the later applicable update first because cumulative updates normally supersede earlier ones.

3. Run a non-repairing component-store scan:

   DISM.exe /Online /Cleanup-Image /ScanHealth
   

4. Record whether DISM reports that the component store is repairable, not repairable, or no corruption detected. A clean scan does not invalidate the Update code; it only means DISM's scan did not find repairable store corruption.

5. Verify protected system files without changing them:

   sfc /verifyonly
   

6. If the computer is managed, open Settings > Accounts > Access work or school and record the connection. Stop before changing servicing policy, update service startup, or source settings.

7. On Windows 11, open Settings > System > Recovery and record whether Fix problems using Windows Update and Reinstall now are present. Microsoft documents this option for Windows 11 22H2 or later when the February 2024 optional update or a later update is installed. It can also be unavailable on managed devices. Its absence is not a new error and is a stop condition for this branch.

8. Establish the threshold for repair action. Continue when the same update produces 0x800F081F after restart/retry and either:

   • DISM/CBS records CBS_E_SOURCE_MISSING;
   • /RestoreHealth in Resolution Branch A also returns 0x800F081F; or
   • DISM/SFC complete but the exact update still fails with the same code.

9. Stop and route elsewhere if the code changes, the target is an optional-feature installation, the update is known to be withdrawn/held, or storage/power is unstable.

Branch A — Repair the component store and protected system files once

1. From an elevated Command Prompt, run:

   DISM.exe /Online /Cleanup-Image /RestoreHealth
   

2. Let the command finish. Do not interrupt it because the percentage appears stationary.

3. Record the complete final message and copy the updated DISM log:

   copy /y "%SystemRoot%\Logs\DISM\dism.log" "%USERPROFILE%\Desktop\WU-0x800F081F\DISM-after-RestoreHealth.log"
   

4. If DISM reports The restore operation completed successfully, run:

   sfc /scannow
   

5. Restart Windows and retry the exact update once.

6. If the update succeeds, proceed to verification. If it again returns 0x800F081F, do not loop DISM/SFC; continue to Branch B or C.

7. If DISM itself returns 0x800F081F and says the source files could not be found, preserve the log. Do not point /Source at an arbitrary ISO, another computer, or an unverified WIM index. Continue to a supported repair reinstall.

Branch B — Windows 11: use Fix problems using Windows Update

1. Confirm the verified backup, stable power, working Internet connection, and adequate free space.

2. Open Start > Settings > System > Recovery.

3. Under Fix problems using Windows Update, select Reinstall now.

4. In the confirmation window, choose whether Windows may restart automatically 15 minutes after installation completes. Save all work regardless of this choice.

5. Select OK. Windows Update downloads and installs a repair version of the current Windows installation.

6. Do not power off, force-restart, run cleanup tools, or start another installer while the repair version downloads or installs.

7. Restart when prompted if automatic restart was not selected.

8. Sign in, allow post-install configuration to finish, and record winver before retrying the target update.

9. Open Windows Update and select Check for updates. If the exact target KB is still applicable, retry it once. If it has been superseded, install the newer offered cumulative update instead.

Branch C — Windows 10 or ineligible Windows 11: perform an in-place repair install

1. Obtain official Microsoft Windows installation media matching the installed Windows generation, architecture, edition, system/default UI or install language, and the intended feature release recorded from winver. Its build/repair level must be the same as or newer than the installed OS. Newer feature-release media is a feature upgrade with separate compatibility and safeguard checks, not this same-version repair branch.

2. Before mounting or starting Setup, capture the installed build and revision from an elevated Command Prompt:

   reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v CurrentBuildNumber > "%USERPROFILE%\Desktop\WU-0x800F081F\installed-build.txt"
   reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v UBR >> "%USERPROFILE%\Desktop\WU-0x800F081F\installed-build.txt"
   dism /Online /Get-CurrentEdition >> "%USERPROFILE%\Desktop\WU-0x800F081F\installed-build.txt"
   dism /Online /Get-Intl > "%USERPROFILE%\Desktop\WU-0x800F081F\installed-language.txt"
   type "%USERPROFILE%\Desktop\WU-0x800F081F\installed-build.txt"
   

   Treat CurrentBuildNumber.UBR as the installed build/revision—for example, build 22631 with UBR 4037 is 22631.4037. Do not infer this value from the ISO filename.

3. Mount the ISO, note its drive letter, and determine whether the image is install.wim or install.esd:

   dir <ISO-letter>:\sources\install.wim
   dir <ISO-letter>:\sources\install.esd
   

   Replace <ISO-letter> with the actual mounted-media letter. Exactly one of those files normally exists. If neither exists, stop; the media cannot be evaluated by this branch.

4. List the media images, identify the index whose edition matches DISM /Online /Get-CurrentEdition, and save the detailed metadata for that exact index. Use only the command matching the file found in step 3:

   dism /English /Get-WimInfo /WimFile:<ISO-letter>:\sources\install.wim > "%USERPROFILE%\Desktop\WU-0x800F081F\media-images.txt"
   dism /English /Get-WimInfo /WimFile:<ISO-letter>:\sources\install.wim /Index:<matching-index> > "%USERPROFILE%\Desktop\WU-0x800F081F\media-selected-image.txt"
   

   Or, for ESD media:

   dism /English /Get-WimInfo /WimFile:<ISO-letter>:\sources\install.esd > "%USERPROFILE%\Desktop\WU-0x800F081F\media-images.txt"
   dism /English /Get-WimInfo /WimFile:<ISO-letter>:\sources\install.esd /Index:<matching-index> > "%USERPROFILE%\Desktop\WU-0x800F081F\media-selected-image.txt"
   

   Replace <matching-index> only after the first listing proves the edition. Inspect media-selected-image.txt. Require the selected image's Version build component to match the installed CurrentBuildNumber, which keeps this in the same feature release, and require its ServicePack Build/revision to be equal to or greater than the installed UBR. If the media is from a different feature release, is older than the installed build/revision, or does not expose enough metadata for an unambiguous comparison, stop and obtain current matching media.

5. Start the repair from within the running Windows installation. Run:

   <ISO-letter>:\setup.exe
   

   Do not boot from the USB/ISO; booting from media does not provide the same keep-apps in-place path.

6. Follow Setup until Ready to install. Read the summary before selecting Install.

7. Require the summary to state the intended Windows edition and feature release and Keep personal files and apps. This final screen is an additional gate; it does not replace the build comparison above.

8. If any of those items do not match, select Change what to keep only to inspect the supported choices. If Keep personal files and apps is unavailable—or if Setup identifies a newer feature release—cancel this repair procedure. Route newer media as a feature upgrade rather than silently changing the purpose of the operation.

9. When the media comparison, summary, and backup are all verified, select Install.

10. Keep stable power. Windows will restart several times. Do not boot from the installation media when the machine restarts.

11. After sign-in, record winver, confirm applications/files are present, and run Windows Update. Retry the exact KB once if it remains applicable.

Branch D — Repair reinstall fails or rolls back

1. Do not immediately repeat Setup.

2. Preserve the displayed code and the setup logs under:

   %SystemDrive%\$WINDOWS.~BT\Sources\Panther
   %SystemRoot%\Panther
   

3. Record setuperr.log and the relevant portion of setupact.log before cleanup removes them.

4. Route the new Setup phase/code to the matching upgrade-repair article. The original 0x800F081F no longer explains a distinct Setup failure.

• DISM/SFC repair and the update succeeds: no repair reinstall is needed; retain the logs until two restarts succeed.
• DISM returns 0x800F081F: DISM corroborates the missing-source condition in another servicing operation on the affected installation; it is not an independent lab reproduction. Use a supported repair reinstall rather than a guessed source.
• Fix problems using Windows Update completes and the update succeeds: component/system-file replacement likely removed the blocker.
• The target KB disappears and a newer cumulative update installs: the superseding update is the relevant verified result.
• Repair Setup rolls back with a new code: preserve Setup logs and diagnose that new code/phase.
• Windows starts but applications/files are missing: stop update work and restore from backup; do not assume a second reinstall will restore them.
• The update still returns 0x800F081F after a successful repair reinstall: preserve new CBS/DISM evidence and escalate to package-specific servicing analysis.

• Do not delete WinSxS, SoftwareDistribution, CBS manifests, catalog files, or servicing registry keys manually.
• Do not run an unreviewed Windows Update reset script.
• Do not use /Source with a random install.wim, wrong image index, wrong language, wrong edition, or different build.
• Do not run /StartComponentCleanup /ResetBase as a repair for missing source files.
• Do not boot from installation media when the objective is to preserve applications in an in-place repair.
• Do not proceed when Keep personal files and apps is absent.
• Do not interrupt DISM or Setup because progress appears stationary.
• Do not disable antivirus, Secure Boot, BitLocker, or update services without separate evidence and a rollback plan.
• Do not rerun the same repair repeatedly after it fails with a new Setup code.

A repair reinstall does not provide a guaranteed one-click undo. The rollback plan therefore starts before installation.

1. Before selecting Reinstall now or Install, cancel if the backup, power, free-space, edition/language match, or keep-apps selection is not verified.

2. If Setup fails and reports that it restored the previous version, sign in and confirm winver, applications, files, networking, and activation. Preserve Setup logs before retrying anything.

3. If the repair completes but the subsequently installed target update causes a regression, open Settings > Windows Update > Update history > Uninstall updates. Uninstall only the exact target quality update when it is listed and removal is appropriate. A servicing-stack or permanently integrated update may not be removable.

4. If Windows cannot start after the target update, use Windows Recovery Environment's Uninstall latest quality update only when the chronology and update type match. Do not use it to pretend the entire repair reinstall was undone.

5. Restore missing personal files from the verified backup. Restore an entire system image only under that image product's tested recovery procedure.

6. If applications/settings were lost despite a keep-apps confirmation, stop and preserve the system. Reinstalling again can overwrite rollback evidence.

1. Run winver and record the repaired Windows edition/version/build.

2. Confirm that the user profile, representative documents, installed applications, network, and activation remain available.

3. Open an elevated Command Prompt and run:

   DISM.exe /Online /Cleanup-Image /ScanHealth
   sfc /verifyonly
   

4. Open Settings > Windows Update > Update history and verify the exact target KB or its superseding update reports successful installation.

5. Restart Windows twice. Recheck Update history after the second restart.

6. Search the new CBS log for 0x800F081F only in entries corresponding to the post-repair attempt. Historical log lines do not mean the current repair failed.

7. Keep the backup and evidence folder until the system has operated normally through at least two restarts and one complete Windows Update scan.

Confidence is approximately 80% that a supported repair reinstall will resolve this class of 0x800F081F Windows Update failure when the exact code repeats after restart, the target update remains applicable, servicing evidence shows CBS_E_SOURCE_MISSING or DISM cannot repair the source, and the repaired system subsequently installs that update or its superseding cumulative update. Two independent source cases reported success through an in-place repair or Windows Update's repair-reinstall feature; TechXplored has not independently reproduced them.

Confidence is lower when only a single failed attempt exists, the update was superseded/withdrawn, the code came from optional-feature installation, or logs do not connect the code to the failed KB.

Stop for unstable storage, inadequate backup/power/space, managed servicing policy, a missing keep-apps option, a Setup rollback with a new code, Windows activation/edition mismatch, or any unexpected file/application loss. After a successful repair reinstall that still produces 0x800F081F, stop repeating the procedure and escalate to package-specific CBS/servicing analysis.