Windows Update 0x800f081f: repair a missing component-store source

Short answer

0x800f081f is CBS_E_SOURCE_MISSING: servicing could not find a required package or repair file. On an affected, elevated device, run DISM component-store repair and then System File Checker. If DISM cannot reach a usable repair source, provide installation media that matches the target Windows release, edition, language, and servicing level; a mismatched image can leave the error unresolved.

This is a source-documented guide, not a repair tested by this site.

Problem / symptoms

A cumulative update, feature installation, or component repair fails and the servicing logs contain 0x800f081f, CBS_E_SOURCE_MISSING, or ResolveSource() unsuccessful.

Environment and scope

Windows component-based servicing on supported Windows client or Server versions. The exact repair source and DISM options depend on the OS image, update source policy, and whether the device can reach Microsoft Update or WSUS.

What the evidence establishes

Microsoft describes the code as a missing source for a package or file and recommends repairing the component store with DISM, followed by SFC. The code alone does not identify which package payload is missing or prove that any arbitrary ISO is a valid source.

Investigation

1. Note the failed update/feature, OS edition and build, servicing source policy, and the timestamp of the failure.
2. Check %windir%\Logs\CBS\CBS.log and %windir%\Logs\DISM\dism.log around that timestamp for the package or payload that could not be resolved.
3. Confirm the device can use its configured repair source. Managed devices may be directed to WSUS or another source by policy.
4. If using installation media, check that the image contains the exact edition and a compatible servicing level. Identify the correct image index instead of assuming index 1.

Root cause

The component store repair operation cannot obtain one or more required files from its configured source. Corruption may be involved, but an unavailable or unsuitable source can produce the same code.

Solution

From an elevated Command Prompt, run the vendor-recommended repair sequence:

DISM.exe /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Restart if requested, then retry the failed update. By default, DISM may use Windows Update as its repair source. Where that source is unavailable, follow Microsoft’s Windows image repair guidance to specify a matching local or network source and the correct WIM/ESD index. Do not guess an index or use media from a different release.

Verification

• Confirm DISM completes successfully and record its exit/result details.
• Confirm SFC completes and reports whether it repaired files or found no integrity violations.
• Retry the same update or feature and check CBS.log for the original source-missing failure.
• If the code remains, use the logs to identify the specific missing payload and source path; do not repeat the same repair blindly.

Vendor sources

• Common Windows Update errors
• Repair a Windows image