Microsoft Windows 11 25H2 Update Version OS Builds 26200.7628 and 26100.7628

KB5078127 is an out-of-band cumulative update for Windows 11 25H2 and 24H2 (OS Builds 26200.7628 and 26100.7628). It fixes app hangs and file errors when opening or saving cloud-based files, and includes prior security and non-security updates.

• Includes security fixes from the January 13, 2026 security update KB5074109 and the January 17, 2026 out-of-band update KB5077744.

• Fixed an issue where some applications became unresponsive or showed unexpected errors when opening or saving files from cloud storage such as OneDrive or Dropbox.
• Fixed an Outlook issue where PST files stored on OneDrive could cause Outlook to hang, fail to reopen, or show missing sent items and re-downloaded emails.

• The password icon might be missing or invisible in lock screen sign-in options after installing KB5064081 or later updates; the password button is still available in the hidden placeholder.

• This update is cumulative and includes previous security and non-security releases plus an additional fix.
• It is offered through Windows Update only to devices that already installed KB5074109 or KB5077744, and is also available from the Microsoft Update Catalog.
• For devices enrolled in Hotpatch, the issue is addressed via KB5078167 without requiring a restart.
• IT administrators using Microsoft Intune or Windows Autopatch should follow the expedited quality update guidance for deployment.

• KB5078127 release notes
  https://support.microsoft.com/help/5078127

Product Information

Vendor: Microsoft

Product: Windows 11

Version: OS Builds 26200.7628 and 26100.7628

Release date: Jan 24, 2026