In an unusual move for a tech giant, Microsoft has publicly advised Windows 11 users to uninstall the January 2026 cumulative update (KB5074109) after reports of widespread system issues emerged across numerous devices. The patch, which was released on January 13 and intended to bolster security and reliability, has instead caused notable problems for many users — particularly those relying on the classic Outlook desktop client, certain cloud storage workflows, and systems with specific hardware configurations. (Gadgets 360)

In this detailed article, we’ll break down what went wrong, how the update affects systems, why Microsoft recommended uninstalling it, and what practical steps users can take to stay secure while troubleshooting the problems.

What Is Update KB5074109?

On January 13, 2026, Microsoft rolled out a security and quality update for Windows 11 editions 24H2 and 25H2 — identified as KB5074109. The update included fixes for more than 100 vulnerabilities and system improvements, such as addressing issues with Neural Processing Unit (NPU) power management and Secure Boot certificates. (Notebookcheck)

Typically, monthly cumulative updates strengthen the operating system and patch known security weaknesses. However, in this case, the patch introduced unexpected side effects that outweighed its intended benefits for certain users and configurations.

Major Problems Reported After Installation

1. Classic Outlook Freezes and Becomes Unusable

One of the most severe issues linked to the update affects users of the classic Outlook desktop client, especially those with POP email accounts or PST (Personal Storage Table) files stored in cloud‑synced folders (like OneDrive). (Gadgets 360)

Affected users have reported that after installing KB5074109:

  • Outlook becomes unresponsive or stuck on “Not Responding” status.

  • Closing Outlook doesn’t actually terminate the process — OUTLOOK.EXE continues running in the background.

  • Sent emails may not appear in the Sent Items folder, or messages may re‑download repeatedly. (Gadgets 360)

These symptoms make it very difficult to use Outlook for daily email tasks, prompting some users to force‑close the application or restart their computers repeatedly. (Gadgets 360)

2. Broken App Functionality and Crashes

Beyond Outlook, users have reported other application problems linked to the update:

  • Apps crash or hang, especially when accessing cloud storage services such as OneDrive or Dropbox. (AlternativeTo)

  • Some systems displayed random black screens or performance instability, particularly on machines with specific GPU configurations. (Notebookcheck)

These reports have surfaced across communities and technical forums, highlighting that the issues are not isolated to a tiny number of users. (reddit.com)

3. Other System‑Level Issues

In addition to Outlook and app crashes, other aspects of Windows 11 were impacted:

  • Problems with shutdown or hibernation in some system builds led Microsoft to release separate emergency “out‑of‑band” updates. (The Verge)

  • Issues with Remote Desktop and login failures occurred on certain configurations, prompting Microsoft to push additional fixes. (Windows Central)

These ongoing stability concerns have contributed to a perception among many users that the update caused broad system regressions rather than improvements.

Why Microsoft Recommends Uninstalling the Update

Microsoft’s public acknowledgment of the problem — and its guidance to uninstall KB5074109 — is significant because companies generally prefer to fix bugs behind the scenes rather than encourage rollback. (Digital Trends)

Here’s why rollback is being suggested:

Fixing the Symptoms

Uninstalling the problematic update has restored normal behavior for many users, especially those with Outlook issues or cloud access problems. (AlternativeTo)

Temporary Mitigation

Since Microsoft has not yet released a permanent fix, rolling back the update serves as a temporary measure to restore usability until a stable patch arrives. (Digital Trends)

Complex Regressions

The nature of some bugs — particularly those involving legacy applications like classic Outlook or cloud storage interactions — means that simple configuration changes or workarounds aren’t always effective. Uninstallation is sometimes the only reliable path to system stability. (Gadgets 360)

How to Uninstall the Update

Microsoft Support provides a built‑in method to remove updates that cause issues:

  1. Open Settings on your Windows 11 device.

  2. Navigate to Windows Update.

  3. Select Update history.

  4. Click Uninstall updates.

  5. Find KB5074109 in the list and choose to uninstall it. (Microsoft Support)

This process removes the problematic patch, but users should be aware that doing so also removes all the security patches and vulnerability fixes that were part of the update. (Microsoft Support)

Risks of Uninstalling Security Updates

Removing KB5074109 may restore functionality — but it also carries risks:

1. Reduced Protection

Security updates patch known vulnerabilities. Without these protections, a device may be more susceptible to malware, exploitation, and unauthorized access. (Microsoft Support)

2. Performance and Stability Concerns

Some updates include performance and reliability fixes in addition to security patches. Uninstalling the update might reintroduce older issues or leave devices without optimizations. (Microsoft Support)

3. Support Considerations

Manufacturers and software providers often require the latest security updates for ongoing support. Removing them can sometimes limit access to support services. (Microsoft Support)

Workarounds Without Uninstalling

If you prefer to keep the security update installed, there are a few temporary workarounds:

Use Outlook Web

Microsoft suggests using the browser‑based Outlook web app, which isn’t affected by the update’s issues. (Gadgets 360)

Move PST Files Out of OneDrive

Some problems appear linked to how PST files stored in sync folders are accessed — relocating them to local storage may reduce errors. (Digital Trends)

Pause Updates

Pausing automatic updates temporarily prevents Windows from reinstalling the problematic update while waiting for a patch. (Digital Trends)

What Microsoft Is Doing Next

Microsoft continues to investigate the root causes of the regressions introduced by KB5074109 and may issue one of the following solutions:

  • A new cumulative update that corrects the faulty behavior while maintaining security patches.

  • A Known Issue Rollback (KIR) that selectively neutralizes the problematic code paths without removing all updates. (Microsoft Support)

  • Additional emergency patches targeted at specific symptoms.

Until a permanent fix is available, users and IT administrators must weigh the trade‑offs between system stability and security exposure.

Conclusion

The unusual situation of Microsoft telling users to uninstall a Windows 11 update underscores the challenges of large‑scale software updates. While KB5074109 was intended to strengthen Windows 11 with vital security patches and system improvements, its side effects — particularly on classic Outlook, cloud‑stored files, and overall stability — prompted an extraordinary rollback recommendation. (Digital Trends)

Uninstallation can restore usability but comes with security trade‑offs, so users should consider their individual needs and risk tolerance. For now, relying on workarounds and waiting for a stable patch release may offer the best balance between protection and performance.

FAQs

1. Why is Microsoft asking users to uninstall an update?
Because the January 2026 cumulative update KB5074109 introduced bugs that caused system instability and app failures for many users, prompting Microsoft to suggest uninstalling it until a fix is ready. (Digital Trends)

2. Does uninstalling the update affect security?
Yes. Removing a security update also removes the protections it provided, which can make your system more vulnerable to threats. (Microsoft Support)

3. Which users are most affected by the update issues?
Users of classic Outlook with POP accounts and PST files stored in cloud‑sync folders like OneDrive have reported the most severe problems. (Gadgets 360)

4. Are there alternative solutions besides uninstalling?
Yes — users can try Outlook web, move PST files off OneDrive, or pause updates while Microsoft develops a more stable patch. (Digital Trends)

5. Will Microsoft fix this problem soon?
Microsoft is investigating and may release a permanent fix through a future update or a Known Issue Rollback (KIR). (Microsoft Support)


Written by : Yousaf Lashari