How to Fix DISM Error 0x800f081f in Windows 11

The Problem

0x800f081f is CBS_E_SOURCE_MISSING — "the source files could not be found". It appears when DISM tries to repair Windows, or when you add an optional feature, and cannot obtain a clean copy of the files it needs to put back.

DISM normally repairs the component store by downloading replacements through Windows Update. That fails when the component store is too damaged to describe what is missing, when Windows Update itself is broken, when a corporate policy points the machine at a WSUS server that has no source files, or when the PC has no working internet connection. The fix in almost every case is to supply the files yourself, from a Windows 11 ISO.

Hitting this specifically while installing .NET Framework 3.5? That is the most common single trigger and has its own walkthrough: fix the .NET Framework 3.5 install error.

Symptoms

• DISM /Online /Cleanup-Image /RestoreHealth stops around 62.3% or 100% with Error: 0x800f081f.
• Settings → Optional features fails to install a feature with the same code.
• sfc /scannow reports corruption it "was unable to fix".
• The DISM log at C:\Windows\Logs\DISM\dism.log contains lines about a missing payload or a source that could not be resolved.

Step 1: Confirm the Real Error First

1. Right-click Start → Terminal (Admin).
2. Check the health state before trying to repair anything:

   DISM /Online /Cleanup-Image /ScanHealth
   

3. If it reports the store is repairable, try the standard repair once more:

   DISM /Online /Cleanup-Image /RestoreHealth
   

4. If it fails again with 0x800f081f, continue to Step 2 — the missing-source path is the fix.
5. Background on both tools: how to run SFC and DISM.

Step 2: Download a Matching Windows 11 ISO

The source must match the build already installed, or DISM will reject it.

1. Press Windows + R, type winver, and press Enter. Note the version (such as 24H2) and the OS build number.
2. Go to Microsoft's official Windows 11 download page and download the Disk Image (ISO) for the same version and the same language and edition.
3. Do not use an ISO from anywhere else. Modified images are the reason many people end up chasing this error a second time.
4. If your installed build is newer than the available ISO, install all pending updates first so the ISO is not older than the system, or run the update from Step 7 instead.

Step 3: Mount the ISO and Find the Image File

1. Double-click the downloaded .iso — Windows mounts it as a drive. Note the letter it gets, for example E:.
2. Open the sources folder on that drive and look for install.wim or install.esd. Both work, but the commands differ slightly.
3. List the editions inside it so you can pick the right index. For a .wim:

   DISM /Get-WimInfo /WimFile:E:\sources\install.wim
   

4. For an .esd, use the same command against install.esd.
5. Note the Index number beside your edition — typically 6 for Windows 11 Pro and 1 for Home, but read the output rather than assuming.

Step 4: Run DISM Against the ISO

1. In Terminal (Admin), using your drive letter and index:

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

2. For an .esd file instead:

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

3. /LimitAccess is the important part — it stops DISM from trying Windows Update, which is what was failing.
4. Let it run to 100%. It can sit at one percentage for several minutes; that is normal.
5. Reboot, then run sfc /scannow to put the repaired files into place.

Step 5: Clear the Policy That Blocks Feature Installs

On PCs joined to a domain, or where someone has tightened settings, a policy can stop Windows fetching feature files entirely.

1. Windows + R → gpedit.msc → Enter. (Windows 11 Home does not include this — use Step 6 instead.)
2. Go to Computer Configuration → Administrative Templates → System.
3. Open Specify settings for optional component installation and component repair.
4. Set it to Enabled, then tick Contact Windows Update directly to download repair content instead of Windows Server Update Services (WSUS).
5. Click OK, then in Terminal (Admin) run:

   gpupdate /force
   

6. Retry the install or repair.

Step 6: Set the Same Option in the Registry

For Windows 11 Home, or where Group Policy is unavailable.

1. Windows + R → regedit → Enter.
2. Navigate to:

   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing
   

   Create the Servicing key if it does not exist.
3. Create a DWORD (32-bit) Value named RepairContentServerSource and set it to 2.
4. Reboot and retry.
5. If the machine is managed by an employer, check before changing this — the policy may be there on purpose.

Step 7: Reset Windows Update and Try Again

If you would rather fix the download path than supply an ISO.

1. In Terminal (Admin):

   net stop wuauserv
   net stop bits
   ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
   net start wuauserv
   net start bits
   

2. Disconnect any VPN and turn off metered connections in Settings → Network & internet.
3. Reboot and run DISM /Online /Cleanup-Image /RestoreHealth again without /Source.
4. More on update problems: fix Windows 11 update errors and fix Windows Update stuck.

Step 8: Repair Install as the Fallback

When the component store is too damaged to repair from any source, an in-place upgrade replaces it wholesale while keeping your files and programs.

1. Keep the ISO mounted from Step 3.
2. Run setup.exe from the root of the mounted drive — not from inside sources.
3. Choose Keep personal files and apps when prompted.
4. Expect 30 to 60 minutes and several restarts.
5. Detail on what this preserves: reinstall Windows without losing data. Back up first: set up automatic backups.

What Not to Do

• Don't use an ISO from a different Windows version or language. DISM will refuse it, and mismatched sources are the most common reason Step 4 fails.
• Don't omit /LimitAccess. Without it DISM goes back to the download path that was already failing.
• Don't download "DISM repair tools" from third-party sites. DISM is built into Windows; those downloads add nothing.
• Don't run /StartComponentCleanup /ResetBase before repairing. It removes the superseded components that a repair might otherwise have used.

Still Not Working?

If a repair install also fails, the underlying storage may be at fault — a component store that keeps re-corrupting usually sits on a drive with problems. Check it: check SSD and hard drive health and fix KERNEL_DATA_INPAGE_ERROR. A clean install is the last resort: how to clean install Windows 11.

Related: fix error 0x80070005, fix error 0x80004005, and fix "there was a problem resetting your PC".