Microsoft Rolls Out Emergency Windows 11 Update to Fix Broken March Preview Patch

Microsoft has released an emergency Windows 11 update to fix the broken March preview rollout that triggered widespread installation failures. The company says the new update, KB5086672, replaces last week's problematic preview KB5079391 for Windows 11 24H2 and 25H2. Microsoft says the patch addresses all of the fixes meant for the March 2026 security and non-security preview updates. It also includes the repair for the installation bug that blocked some systems from completing the earlier update.

KB5079391 included fixes from earlier March patches. However, users reported that the update failed to install—often resulting in error code 0x80073712—then kept reappearing in Windows Update. In response, Microsoft paused the rollout of KB5079391 and prepared the out-of-band KB5086672 package.

One more thing about the new update is that KB5086672 acts as a full cumulative update, so devices that skipped or failed KB5079391 can install the new patch and still get ...