0x800f081f — Source files not found – How to Fix

The Windows error code 0x800f081f, “Source files not found,” usually appears when you try to install or update optional Windows features such as .NET Framework, or when running Windows Updates. It means Windows cannot locate the necessary files to complete the process. While it might look serious, this problem is often resolved by pointing Windows to the correct installation source or repairing corrupted system files.

Have a different error code? Figure out how to fix it with our free Windows error code decoder.

Causes

Several factors can trigger error 0x800f081f:

• Windows Update cannot access the required feature files
• The installation source is missing or does not match the system’s build/edition
• Corrupted component store or system files
• Disabled Windows Update service preventing downloads
• Misconfigured Group Policy preventing Windows from retrieving files online

Fixes

Run DISM with a source

The most reliable fix is to supply DISM with a valid installation source:

1. Mount a Windows ISO that matches your system’s version and build.
2. Note the drive letter (e.g., D:).
3. Run the following command in an elevated Command Prompt: DISM /Online /Cleanup-Image /RestoreHealth /Source:wim:D:\sources\install.wim:1 /LimitAccess Replace D: with the mounted ISO drive letter.
   This tells DISM to use the ISO files instead of trying (and failing) to pull from Windows Update.

Ensure source matches build and edition

If the ISO doesn’t exactly match your installed Windows version, DISM will fail. Verify the build number with:

winver

Then download an ISO from Microsoft that matches both the build and edition (e.g., Home, Pro, Enterprise).

Run System File Checker (SFC)

Once DISM succeeds, run:

sfc /scannow

This repairs any lingering corrupted or missing files that may have been preventing updates or feature installs.

Enable access to Windows Update

If Group Policy is set to block Windows from retrieving files online, you may see this error. To fix:

1. Open the Group Policy Editor (gpedit.msc).
2. Navigate to Computer Configuration → Administrative Templates → System.
3. Open Specify settings for optional component installation and component repair.
4. Set it to Enabled and check Contact Windows Update directly.
   This allows Windows to download required files if no local source is available.

Additional troubleshooting

• Check Windows Update service: Ensure services like wuauserv and bits are running. Restart them if necessary.
• Free up system drive space: Lack of disk space can prevent temporary file storage.
• Perform an in-place upgrade repair: If corruption persists, use the latest Media Creation Tool to repair Windows without erasing files.

Conclusion

The 0x800f081f — Source files not found error typically occurs when Windows doesn’t have access to the correct feature files. Pointing DISM to a valid ISO source, ensuring build compatibility, and repairing the system image usually solves the problem. For persistent cases, enabling Group Policy settings or performing a repair install restores full functionality.

Have a different error code? Figure out how to fix it with our free Windows error code decoder.