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If your Windows 11 PC started acting strangely after last week’s update, you’re far from alone. Microsoft’s latest cumulative update, released on January 13, 2026, is causing significant headaches for a growing number of users, with reports of black screens, broken apps, and system instability flooding online forums and support channels.
The update in question, KB5074109, is a mandatory security and reliability patch for Windows 11 versions 24H2 and the newer 25H2. While it includes important fixes—notably a power-related correction for devices with Neural Processing Units (NPUs)—its aftermath has been messy. For many, the cure has felt worse than the disease.
A Cascade of User Reports Points to KB5074109
Across Reddit, Microsoft’s own Answers forum, and tech support communities, a consistent narrative has emerged: problems began immediately after installing last Tuesday’s patch.
- Black Screens & Display Instability: A prominent wave of complaints involves random black screens or full display failures, often requiring a hard reboot. This issue appears disproportionately reported by users with NVIDIA graphics cards, though it’s not exclusive to them. Some found their systems unbootable, forced to enter Safe Mode or the Windows Recovery Environment to regain control.
- Apps That Won’t Launch: From built-in utilities like Notepad and the Snipping Tool to third-party software, numerous applications are reportedly failing to open. Error codes like
0x803F8001are common, leaving users unable to access essential programs. - Acknowledged Outlook Classic Breakdown: Microsoft has officially confirmed one major regression. Users of the classic Outlook desktop app with POP email accounts—especially those who store their PST data files within OneDrive—may find the application hanging and refusing to close or reopen properly.
For this specific Outlook issue, Microsoft has published official guidance detailing workarounds, such as moving PST files out of OneDrive folders.
Microsoft’s Evolving Stance: Uninstall as a Valid Fix
As the volume of trouble reports grew, Microsoft’s public posture shifted. What began as isolated support suggestions has become a broader, tacit acknowledgment. On its support forums and through agent guidance, uninstalling KB5074109 is now being treated as an acceptable and supported mitigation for severely affected users.
This sentiment is echoed in broader tech reporting, with outlets noting the company's direction for impacted users to roll back the update.
The company has already rushed out out-of-band (OOB) updates to address some critical regressions from the January patch cycle, including Remote Desktop sign-in failures. However, the core stability complaints surrounding black screens and app failures on 24H2 and 25H2 remain unresolved for many.
What Should You Do? A Practical Guide
Faced with a potentially unstable system, the decision isn't always straightforward. Here’s the consensus from experts and the emerging practical reality:
- If Your PC is Running Fine: Leave the update installed. It contains crucial security patches that protect your system. Don’t preemptively remove it based on others’ reports.
- If Your System Became Unstable After January 13th: If you’re experiencing black screens, persistent app crashes, or the confirmed Outlook hang, uninstalling KB5074109 is the recommended stopgap solution. You can remove it via Settings > Windows Update > Update history > Uninstall updates. A restart will be required.
For a detailed walkthrough of this process and the broader context of Microsoft's recommendation, see this report: Microsoft Urges Uninstalling Update KB5074109 After Bug Reports on Windows 11: Here’s How.
- If You Can’t Boot Normally: Use the Windows Recovery Environment (accessed by interrupting the boot process three times) to remove the update from there.
The Security Trade-Off
This situation puts users in a difficult position. Microsoft and security analysts consistently warn that uninstalling a security update re-exposes your computer to the vulnerabilities it was meant to fix. The pragmatic advice, however, has crystallized: stability first. For users with a crashed or unusable machine, removing the update to restore functionality is the necessary first step. The plan should be to reapply the fixes once Microsoft issues a revised, stable build.
The community is actively tracking developments, and users are sharing their experiences and workarounds on the Microsoft Answers forum thread for KB5074109.
For those affected by the Outlook-specific problem, Microsoft’s full workaround details are available in their support document: Classic Outlook profiles with POP accounts and PSTs hang after Windows updates on January 13, 2026.
The episode underscores the perennial challenge of balancing critical security delivery with system stability, a balance that, for many this month, was lost. All eyes are now on Microsoft to release a follow-up patch that delivers the promised security without the side effects.