Latest Security Update Fails to Install

For persistent failures installing the latest Windows security update on Windows 10, the context shows that in several similar cases the reliable resolution was to repair or reinstall Windows in-place, then re-run Windows Update.

From the referenced Windows 10 and Windows 11 update issues:

• When a specific KB repeatedly fails with various troubleshooting attempts (DISM, SFC, clean boot, manual CAB/MSU install), an in-place repair install of Windows has resolved the corruption and allowed the problematic update to install normally.
• In some cases, the failed update also caused application issues (for example, Outlook corruption), which were also corrected by the in-place reinstall.

Recommended remediation path based on these cases:

1. Back up important data.
2. Perform an in-place repair install of Windows 10 (using the same or newer build media), choosing the option to keep apps and files.
3. After the repair completes, run Windows Update again and install the latest cumulative/security updates.

If the update still fails after an in-place repair, contact Microsoft Support and provide Windows Update logs (CBS.log, WindowsUpdate.log) for deeper analysis, as done in the referenced scenarios.

References:

• Latest Security Update KB5079473 (26200.8037) Fails to Install - Microsoft Q&A
• KB5058713 fails install - Microsoft Q&A
• HOW CAN Windows 11, version 25H2 Install error - 0x800f081f BE FIXED? - Microsoft Q&A
• windows 11version 25H2 couldn't install, error 0x80070476 - Microsoft Q&A
• Contacting Microsoft Support With an Update Related Question (KB5071959) - Microsoft Q&A
• Servicing Stack Updates (SSU): Frequently Asked Questions