Windows System Errors
Source Files Not Found
0x800F081FReviewed for reference consistency: August 11, 2026
Source Files Not Found
What 0x800F081F Means
The 0x800F081F error on the Windows System Errors indicates source files not found. This typically occurs due to feature-on-demand payload files missing from the winsxs component store, for example .net framework 3.5 sources.
A component install can lose its source files: 0x800F081F means Windows cannot locate the payload — typically a legacy feature or .NET Framework 3.5 whose payload is absent from the local store.
Technical Background
Windows depends on the WinSxS (Side-by-Side) component store for feature payloads. If a legacy feature is requested but its payload was pruned to save disk space, Windows tries to fetch it from an external source.
If Windows cannot access the internet or the mounted ISO, it throws 0x800F081F.
Common Causes
- Feature-on-demand payload files missing from the WinSxS component store, for example .NET Framework 3.5 sources
- A corrupted Deployment Image Servicing and Management (DISM) source
- Blocked access broadly affecting Component Store networks
Typical Scenarios
- A user attempts to enable legacy DirectPlay features but Windows cannot find the installation media locally.
- DISM fails to repair a broken system image because Windows Update services are blocked.
What to Know
Provision of an offline installation ISO source or unblocking Windows Update access allows DISM to locate and integrate the required components.
Frequently Asked Questions
Common questions about Windows 0x800F081F error
Pointing Windows at a valid installation media path, or allowing Windows Update to download the missing payload, is the standard resolution.
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