This guide covers Windows 11 when you can reach the desktop and run an elevated Command Prompt. It is not an offline repair guide for a PC booted from installation media. If there is no error yet and the percentage simply stopped moving, start with how to tell whether DISM has finished.

Confirm the error and where it happened

Microsoft lists 0x800f081f as CBS_E_SOURCE_MISSING. Record the full message, not just the code. Also note whether you used a plain RestoreHealth command or supplied a source yourself.

What happened Check next
The default repair failed Windows Update access and any organization-managed update policy
Repair failed after adding an ISO source The actual file, image index and source contents
The specified file cannot be found Drive letter and filename in File Explorer
This is a work or school PC Send the command and error to your administrator
You cannot start Windows Use recovery guidance for that environment, not this Online example

The code alone does not prove your drive is failing or your personal files are damaged. Keep the diagnosis narrower than that.

1. Try the normal repair with update access

Save your work, check your backup and connect a laptop to power. Finish any pending restart shown in Windows Update. Open Command Prompt as administrator, then run:

DISM.exe /Online /Cleanup-Image /RestoreHealth

Here, /Online targets the Windows installation that is currently running. Do not add /LimitAccess to this first attempt: that switch blocks Windows Update as a repair source. On a managed PC, ask the administrator to check the approved source instead of changing update policies yourself.

Wait for the final result and the prompt to return. A successful repair takes you to the SFC step below. Another source error takes you to source verification; opening several repair windows will not resolve the missing files.

2. Record your Windows details before choosing media

Run winver from Windows key + R and record the version and OS build. Open Settings → System → About for the edition and system type. Keep the installed language information with these notes.

Detail Why you need it
Edition The image list may include both Home and Pro
Version and build A familiar ISO filename is not proof of suitable repair contents
System type Check whether the PC uses x64 or Arm64
Language Required language components must be available

Use the Microsoft Windows 11 download page for official media. A newly downloaded ISO is not automatically a suitable source for every installed build. Microsoft warns that an older servicing level or missing language components can cause repair to fail.

If you cannot establish that the source is suitable, skip the command example and consider the Windows Update repair option below. Do not download an isolated replacement system file from an unknown site.

3. Find the image index in an actual WIM file

Mount your ISO and open its sources folder in File Explorer. The following example assumes that the mounted drive is E: and that install.wim actually exists. Replace the drive letter if yours is different.

DISM.exe /Get-ImageInfo /ImageFile:E:\sources\install.wim

Read the image names and index numbers. Select the entry for the edition you recorded. Do not assume index 1 is correct or that Pro is always index 6.

If the matching entry really is index 6, inspect it with:

DISM.exe /Get-ImageInfo /ImageFile:E:\sources\install.wim /Index:6

Check the edition, architecture and languages. These commands inspect the image; they do not perform the repair.

If the folder contains install.esd or split install.swm files instead, stop using this WIM example. Renaming the extension is not a conversion. Do not substitute boot.wim just because it happens to be a WIM file.

4. Run the repair using the source you checked

This example is valid only for an actual E:\sources\install.wim with the matching image at index 6. Use your verified path and index in the elevated Command Prompt:

DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:wim:E:\sources\install.wim:6 /LimitAccess

The source argument selects the image. /LimitAccess keeps this attempt from using Windows Update as a fallback. It does not make an incomplete image sufficient.

If the same error returns, do not cycle through random index numbers. Recheck the source conditions and keep the log from this attempt. A command copied correctly can still fail when the image does not contain the files Windows needs.

5. After DISM succeeds, run SFC and test the original problem

Once DISM reports success, run:

sfc /scannow

Read the final SFC result, restart, and retry the update or application that originally failed. Treat those as two checks: the repair tool completed, and the original symptom is gone. If SFC reports files it could not repair, continue with SFC result handling rather than repeating the entire sequence indefinitely.

When matching a repair source becomes the harder problem

On supported Windows 11 PCs, check Settings → System → Recovery → Fix problems using Windows Update → Reinstall now. This reinstalls the current Windows version while retaining apps, files and settings. It is a different option from Reset this PC.

Keep a separate backup, power and internet connection. The option may be absent on managed devices or PCs missing the required Windows updates. If it is absent, do not substitute a reset without checking what each recovery choice keeps.

Keep enough evidence for the next person to help

Save the full error, the command used, the attempt time, Windows version and build, and the selected image index. The default DISM log is %WINDIR%\Logs\DISM\dism.log. Match entries to the latest attempt so that an old failure does not get mistaken for the current result.

Before sharing a log publicly, remove usernames and internal paths. These details make a support request actionable without exposing your whole system history.