Microsoft’s January 13, 2026 cumulative update for Windows 11 is quickly gaining a reputation for the wrong reasons. While the patch is meant to improve security and reliability, a growing number of users say the update, KB5074109, triggered serious stability problems right after installation.
KB5074109 moves Windows 11 25H2 and 24H2 forward to OS builds 26200.7623 and 26100.7623. Alongside the usual monthly security changes, it also includes reliability improvements and a power-related fix aimed at certain devices equipped with a Neural Processing Unit (NPU). But for some PCs, the update appears to introduce new headaches instead of solving old ones.
As complaints spread across Windows discussion boards and support channels, one message has started to stand out: uninstalling KB5074109 is increasingly being treated as a valid short-term workaround for people who are hit by the worst issues.
What users report after installing KB5074109
The problem reports aren’t all identical, and some appear tied to specific hardware or setups, but a few recurring themes keep showing up.
One of the most alarming complaints involves random black screens and display instability soon after the update is installed. Several reports mention systems using NVIDIA graphics hardware, though the issue may not be limited to one brand or model. In the most severe cases, users say their PCs became difficult to start normally, forcing them to boot into Safe Mode or use the Windows recovery environment just to remove the update and get back to a functioning desktop.
Another cluster of reports focuses on apps failing to launch. Users describe programs refusing to open and returning error codes such as 0x803F8001. This reportedly affects built-in Windows tools like Notepad and Snipping Tool, plus various third-party apps and vendor utilities, turning what should be a routine security patch into a productivity blocker.
Microsoft acknowledges Outlook Classic issues
Not all the fallout is unofficial. Microsoft has confirmed a separate issue affecting classic Outlook after the January 13 Windows updates.
According to Microsoft, some users who rely on POP account profiles—and profiles that use PST files, especially when those PST files are stored in OneDrive—may see Outlook hang or fail to close correctly. When Outlook doesn’t exit properly, it can prevent the app from reopening normally, leaving users stuck until they troubleshoot the profile or storage setup.
Microsoft’s current guidance includes practical workarounds, such as moving PST files out of OneDrive or using alternative access approaches until a permanent fix is available.
Emergency fixes arrived, but major complaints remain
After Patch Tuesday, Microsoft also released emergency out-of-band updates aimed at specific regressions, including Remote Desktop sign-in failures and certain shutdown-related problems impacting Windows 11 23H2.
However, many of the ongoing user complaints tied to KB5074109—particularly black screen issues and app-launch failures on Windows 11 24H2 and 25H2—continue to surface. Some users also report problems related to sleep and resume behavior on certain devices, though these power-state issues seem to vary by hardware configuration and haven’t been broadly confirmed in the same way as the Outlook Classic POP/PST problem.
Should you uninstall KB5074109 or keep it installed?
If your Windows 11 PC is running normally after installing the January 2026 update, the safest general advice is to leave it installed. Monthly cumulative updates include critical security patches, and removing them can leave your system more exposed to vulnerabilities that the update was designed to fix.
But if your computer started acting up immediately after KB5074109—black screens, repeated crashes, apps refusing to launch, or Outlook Classic hanging—uninstalling the update is now widely discussed as a supported stopgap while Microsoft works toward a more complete resolution.
Most users can remove the update through Settings by going to Windows Update history, choosing to uninstall the update, and restarting. If your PC won’t boot properly, the update can also be removed using the Windows recovery environment.
The trade-off is simple but important: rolling back a security update can increase risk, but leaving a PC in an unstable, unreliable state can be just as damaging in real life—especially if it interrupts work, school, or access to essential apps. For many affected users, the practical approach is to stabilize the system first, then reinstall security fixes once Microsoft releases a corrected build or additional patches that fully resolve the instability.
