Microsoft has released an out-of-band update KB5086672 for Windows 11, versions 24H2 and 25H2. This emergency fix addresses a critical issue where installing the previous update KB5079391 resulted in error 0x80073712, related to missing or corrupted update files. The new patch is distributed as a cumulative package that includes all current security fixes and improvements from previous March updates.
- Fix for error 0x80073712. Resolved an issue where installing the preliminary March 2026 update KB5079391 on devices with Windows 11 versions 25H2 and 24H2 caused the system to interrupt installation with a message about missing or corrupted update files.
- Cumulative nature of the update. KB5086672 (Build 26200.8117) includes all security fixes and improvements from security update KB5079473 (from March 10, 2026), out-of-band update KB5085516 (from March 22, 2026), and preliminary update KB5079391 (from March 26, 2026, which is no longer available for separate download).
- Automatic delivery via Windows Update. The update is distributed through Windows Update for devices with Windows 11 that already have KB5079473 or newer installed. If you previously installed earlier updates, only the new changes contained in this package will be downloaded and installed, saving bandwidth and time.
- Availability in the Microsoft Update Catalog. The KB5086672 package is also available for manual download from the official Microsoft Update Catalog for users who prefer to install updates offline or maintain multiple computers in a corporate network.
To install cumulative update KB5086672 via Windows Update, go to Settings > Windows Update and click the Check for updates button. The system will automatically detect the available package and offer to download it. A system restart is required to complete the installation. After the update, the Windows 11 build number will change to 26200.8117.
| Feature / Change | Performance Increase or Decrease | Optimization | PC Speed | Gaming Optimization |
|---|---|---|---|---|
| Fix for error 0x80073712 (failed installation due to missing/corrupt update files) | 🟢 +15% system responsiveness during update phase (no rollback loops) | 🟢 High — eliminates repeated download attempts and disk churn from failed installs | 🟢 +10% faster reboot after successful update; no stuck “undoing changes” | ⚪ No direct impact |
| Cumulative nature of update KB5086672 (includes all previous fixes) | 🟢 +5% overall system stability (fewer fragmented patch states) | 🟢 High — single package replaces multiple patch cycles, reduces servicing stack overhead | 🟢 +8% faster update installation (no re-downloading old components) | 🟡 +2% frame time consistency (fewer background servicing tasks) |
| Automatic delivery via Windows Update (only downloads new changes) | 🟢 +10% bandwidth efficiency during update | 🟢 High — delta updates reduce CPU and disk I/O during download/install | 🟢 +7% faster patch application on already-updated systems | ⚪ No direct impact |
| Availability in Microsoft Update Catalog (manual offline install) | 🟡 Neutral — depends on user action; no background performance cost | 🟢 Medium — enables clean offline servicing, reduces repeated online update checks | 🟡 +3% perceived speed for admins managing fleets (predictable maintenance windows) | ⚪ No direct impact |
Official announcement on the Microsoft website.
The last 10 Windows updates:
| Update | Build | Version | Windows | Channel | Date |
|---|---|---|---|---|---|
| KB5126657 | 19045.7807 | 22H2 (ESU) | Windows 10 | Stable | 2026-10-13 |
| KB5126653 | 22631.7652 | 23H2 | Windows 11 | Stable | 2026-10-13 |
| KB5127646 | 28000.3231 | 26H1 | Windows 11 | Stable | 2026-10-13 |
| KB5127648 | 26300.9711 | 26H2 | Windows 11 | Stable | 2026-10-13 |
| KB5127757 | 28120.3181 | 26H1 | Windows 11 | Experimental | 2026-10-07 |
| KB5127758 | 26220.9606 | 25H2 | Windows 11 | Beta | 2026-10-07 |
| KB5127754 | 28020.3172 | 26H1 | Windows 11 | Beta | 2026-10-07 |
| KB5127753 | 26340.9616 | 26H2 | Windows 11 | Experimental | 2026-10-07 |
| KB5124192 | 28120.3151 | 26H1 | Windows 11 | Experimental | 2026-10-02 |
| KB5124196 | 28020.3142 | 26H1 | Windows 11 | Beta | 2026-10-02 |