Microsoft's Patch Tuesday on Jan. 13 intended to close more than a hundred security holes — but for many users the update introduced a new set of headaches. Systems that would not shut down, Remote Desktop sign‑in failures, apps that refuse to open and classic Outlook profiles freezing have all been traced back to the January cumulative build (KB5074109 and related bits). Microsoft has pushed emergency fixes for some bugs, but several problems remain, and some of the recommended remedies are uncomfortable: uninstalling security updates or moving PST files out of OneDrive.

What went wrong (short version)

  • The January security rollup bundled more than 100 fixes. Some of the patched components didn’t play nicely with existing boot protections, cloud‑stored mail data and licensing checks.
  • Microsoft shipped out‑of‑band fixes after reports surfaced: fixes for Remote Desktop authentication and for systems that wouldn’t shut down (System Guard Secure Launch interaction). Those patches landed as emergency updates in mid‑January, but they don’t cover every affected scenario.
  • The sticky, unresolved issue for many is classic Outlook (POP/PST) hanging when PSTs are stored on OneDrive; Microsoft has recommended temporary workarounds rather than issuing an immediate permanent fix.

    • Who is affected

    The troubles have touched a broad swath of Windows customers across client and server SKUs, including multiple Windows 11 builds (25H2, 24H2, 23H2) and Windows 10 22H2 plus several Enterprise LTSC and Server versions. If you rely on legacy Outlook profiles with PSTs — especially when those PSTs live inside OneDrive folders — you should assume you're at risk of hangs or repeated message redownloads.

    The visible symptoms

    You may see one or more of the following:

  • Machines fail to shut down, restart or hibernate (often when Secure Launch is enabled).
  • Remote Desktop prompts for credentials repeatedly or refuses to authenticate.
  • Classic Outlook shows “Not Responding”, refuses to exit cleanly, loses sent items, or keeps redownloading messages.
  • Apps error with codes like 0x803f8001 (Store license problems) or crash when opening or saving files to cloud storage such as OneDrive or Dropbox.
  • Some users report black screens on systems with certain GPU drivers after installing the update.

    • What Microsoft has already done

  • An out‑of‑band update (pushed Jan. 17) addressed Remote Desktop sign‑in failures for affected versions.
  • Another emergency patch fixed the Secure Launch shutdown/hibernate problem for builds where that protection is enabled by default.
  • Microsoft has acknowledged the Outlook POP/PST hang when PSTs live on OneDrive but has not yet shipped a universal fix; instead the company published mitigation guidance and said it will document fix guidance as soon as available.

    • Practical steps you can take today

    If your PC is showing trouble, here are pragmatic options arranged from least to most disruptive.

  • Pause updates temporarily. This prevents the problematic build from being reinstalled while you troubleshoot.
  • Use webmail as a stopgap for Outlook problems. The web interface bypasses the local PST and OneDrive interactions that are causing hangs.
  • Move PST files out of OneDrive to local storage if you can safely do so. That avoids the OneDrive‑sync behaviour implicated in the Outlook bug, but make a verified backup first.
  • If the issue is severe and the above doesn’t help, uninstall the January cumulative update (KB5074109) to roll back to the previous build. Many users have reported success returning to a stable state this way. The typical path is: Settings > Windows Update > Update history > Uninstall updates, then choose the January build and restart. Note: some users run into rollback errors such as 0x800f0905 when uninstalling; if that happens, search for targeted troubleshooting steps or consult your IT team.
  • Install Microsoft’s out‑of‑band hotfixes where Microsoft has published them for your specific Windows build — these address the Remote Desktop and shutdown issues for qualifying systems.

    • A harsh reality: uninstalling a security update exposes you to the vulnerabilities that patch fixed. Weigh that risk — particularly if your device is internet‑facing or used for work — before rolling anything back.

    A pattern, not an accident

    This episode is part of a longer string of update‑related problems that have dogged Windows in recent releases. Last year’s feature updates and earlier security rollups also produced side effects for businesses and consumers — from BitLocker recovery prompts to compatibility headaches. If you’ve been managing Windows fleets you’ll recognize the uncomfortable tradeoff: delaying patching can leave you exposed to active exploits; installing quickly can reveal regressions only visible at scale.

    If you’re interested in how past updates created urgent remediation workflows, see the October update that triggered BitLocker recovery prompts on business PCs and why administrators had to scramble Windows October update triggers BitLocker recovery prompts on business PCs. For users running Windows 11 25H2 who want a lighter, less bloated install surface to reduce upgrade surface area, this guide about decluttering 25H2 can help streamline what’s on your machine How to declutter Windows 11 25H2.

    When to call IT (or Microsoft support)

  • If machines won’t shut down and you can’t apply the specific out‑of‑band fix for your build, get IT involved — persistent power drain on laptops or servers staying on after hours can have broader operational impact.
  • If Outlook is your primary business client and PST corruption or data loss is suspected, stop using the affected profile and involve support; moving PSTs or uninstalling updates without a verified backup can complicate recovery.
  • If you manage many devices, treat this as a triage problem: identify affected groups, block rollout to unaffected ones, and stage remediation with testing before broad redeployment.

Microsoft has fixed some of the worst symptoms, but not everything. For now the most sensible posture for users is cautious: back up mail and important files, apply the targeted emergency updates Microsoft has issued for your OS build, and only uninstall the January rollup if you understand the security tradeoffs and have a recovery plan. This update cycle reinforces an uncomfortable truth: in a complex ecosystem, patches can sometimes introduce new problems even as they close real risks.

WindowsMicrosoftUpdatesOutlookSecurity

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