How do I fix error 0x80070306 when installing Update KB5127648

The screenshot shows KB5127648, build 26300.9711, so use Windows 11’s Fix problems using Windows Update repair option, which reinstalls the current Windows version while preserving files, applications, and settings.

Repair Windows and reinstall the update

1. Back up important personal files as a precaution.
2. Keep the computer connected to power and the internet.
3. Open Start → Settings → System → Recovery.
4. Under Fix problems using Windows Update, select Reinstall now.
5. Select OK and let Windows download and install the repair version.
6. Restart when prompted.
7. Return to Settings → Windows Update → Check for updates and install KB5127648.

This process repairs Windows system files and components without removing your applications, files, or settings.^1^

Confirm the update identity

The question text mentions KB5074109 / build 26200.7623, but that is the January 13, 2026 update.^2^

The screenshot instead shows KB5127648 / build 26300.9711, the October 13, 2026 update for Windows 11 version 26H2. KB5127648 also applies to versions 25H2 and 24H2 with builds 26200.9711 and 26100.9711 respectively.^3^

If “Reinstall now” is unavailable

That option can be absent when the PC is managed by work or school, controlled through Windows Update policies, or lacks the required earlier servicing updates.^1^

Repair the component store and protected system files instead:

1. Search for Command Prompt.
2. Select Run as administrator.
3. Run these commands in order:

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

4. Wait for each command to finish successfully.
5. Restart Windows, then select Settings → Windows Update → Check for updates.

Microsoft’s Windows Update guidance specifies DISM first, followed by SFC, before retrying the update.^4^

If DISM or SFC reports that it cannot complete the repair, or the repair reinstall also fails, open the Get Help application, enter Windows Update error 0x80070306, and proceed to Microsoft support from the diagnostic results. The KB5127648 release notes do not list error 0x80070306 as a known package-specific issue, so there is no documented need to remove or block this update.^3^

References

1. Fix issues by reinstalling the current version of Windows
2. January 13, 2026—KB5074109 (OS Builds 26200.7623 and 26100.7623 ...
3. October 13, 2026—KB5127648 (OS Builds 26300.9711, 26200.9711 and 26100.9711)
4. Windows 11