Cumulative update for Windows 10 22H2 (KB126657) Failed to install 0x80073701

Run DISM and SFC from an elevated Command Prompt, restart Windows, and then retry KB5126657; Microsoft identifies 0x80073701 as a missing component-store assembly and prescribes this repair sequence.^1^

1. Repair the Windows component store

1. Select Start, type cmd.
2. Right-click Command Prompt and select Run as administrator.
3. Run these commands in order. Allow each one to finish, even if progress appears paused:

DISM.exe /Online /Cleanup-Image /RestoreHealth
SFC.exe /Scannow
shutdown /r /t 0

DISM repairs the Windows component store used to install updates; SFC then repairs protected system files. DISM and CBS results are recorded under %SYSTEMROOT%\Logs\CBS.^2^

After the restart:

1. Open Settings > Update & Security > Windows Update.
2. Select Check for updates.
3. Confirm whether KB5126657 installs and whether winver reports OS build 19045.7807. KB5126657 is the October 13, 2026 update for Windows 10 22H2 under the ESU servicing path.^3^

The KB126657 in the title appears to be a transposition; verify that Update history shows KB5126657.

2. If Windows Update still fails, install the x64 package manually

Download the Windows 10 Version 22H2 for x64-based systems package from the Microsoft Update Catalog, close other applications, and run the downloaded .msu file as administrator.^4^

A closely matching KB5126657 case recommends the offline .msu package when the normal Windows Update installation fails.^5^

Do not reset permissions on C:\Windows\WinSxS; that is not the recommended repair for this error and can create additional servicing problems.

3. If DISM or the manual package fails

Record the exact final DISM or installer error, then collect the component-based servicing logs:

1. Open File Explorer and enter: %windir%\Logs\CBS
2. Copy the CBS folder to the Desktop. Copying first avoids errors caused by active log files.
3. Compress the copied folder into a ZIP file.
4. Review the latest CBS.log for 0x80073701, ERROR_SXS_ASSEMBLY_MISSING, or Failed to resolve package.

The missing package named near that entry determines the next repair source; it should not be guessed. If seeking help on Microsoft Q&A or from Microsoft Support, provide the ZIP together with the output of winver and the final DISM result. CBS-log collection is also the recommended escalation for a failed KB5126657 offline installation.^5^

Also verify servicing eligibility: Microsoft’s KB5126657 page lists Windows 10 22H2 under Windows 10 ESU. If the laptop is not enrolled in the applicable Extended Security Updates path, establish that eligibility before treating a subsequent applicability or licensing message as component corruption.^3^

References

1. Windows Update common errors and mitigation
2. Fix Windows Update corruptions and installation failures
3. October 13, 2026—KB5126657 (OS Builds 19045.7807 and 19044.7807 ...
4. Microsoft Update Catalog
5. Error with Windows Update KC5126657 - Microsoft Q&A