Microsoft Releases Windows 10 KB5126657 ESU Update With Storage and Backup Fixes

During the October Patch Tuesday rollout on October 13, Microsoft deployed the KB5126657 update to systems enrolled in the Windows 10 Extended Security Updates (ESU) program. Specifically, this cumulative package targets Windows 10 versions 22H2 and 21H2, advancing the operating system builds to 19045.7807 and 19044.7807, respectively.

Canadian Time Zone and Daylight Saving Adjustments

First, the update implements updated timekeeping rules across several Canadian regions. It enables permanent Daylight Saving Time for the provinces of British Columbia and Alberta, a transition scheduled to take effect officially in November 2026. Additionally, the patch introduces a dedicated Manitoba Standard Time zone, designated in system settings as (UTC-5:00) Manitoba.

ReFS External Storage Security Auditing

For enterprise storage management, the release adds security auditing capabilities and optional policy controls for Resilient File System (ReFS) volumes mounted on external storage media. By default, the system enables the auditing function while leaving strict enforcement policies disabled. Consequently, IT administrators gain ample time to evaluate their environments and prepare for future security hardening.

At this stage, the mechanism strictly generates audit logs without blocking any read or write operations, serving as a preparatory step for upcoming security enforcement. Nevertheless, Microsoft advises organizations that utilize external ReFS drives for backups, disk imaging, or data transfers to review these generated audit logs carefully.

Fixes for Storage Spaces Direct and File History

Furthermore, the patch resolves a critical storage bug where certain Storage Spaces Direct (S2D) virtual disks remained offline following a Windows Update reboot. Previously, the recovery sequence mistakenly flagged valid tiered-storage metadata as corrupted, preventing virtual disks and their hosted workloads from coming back online. Installing this update eliminates the issue entirely without requiring manual workarounds.

Meanwhile, engineers also addressed a persistent flaw within the File History backup utility. Prior to this release, File History frequently failed when backing up or restoring files to external hard drives or network shares. Even when the target drive remained properly connected, the operating system erroneously displayed a prompt instructing users to reconnect their drive. Because affected machines silently halted scheduled backups, administrators should manually open the File History control panel after updating to verify that recent backups completed successfully.

Ongoing Secure Boot Certificate Deployment

Finally, the October update continues the phased distribution of updated Secure Boot certificates. Using targeted device telemetry, Microsoft automatically delivers the replacement certificates to eligible hardware. Although the rollout remains gradual, machines that have not yet received the new certificates can still boot normally and install monthly Windows updates ahead of the original certificate expirations in 2026.