Tag: KB5074109

  • Windows 11 Boot Failures Linked to Series of Bad Updates

    Windows 11 Boot Failures Linked to Series of Bad Updates

    Key Takeaways

    1. The January 2026 KB5074109 update is not randomly causing failures; it affects devices already unstable from a December 2025 update.
    2. The issue primarily impacts a small number of physical Windows 11 devices in commercial settings, not virtual machines.
    3. Microsoft is working on a partial fix to prevent more devices from entering a no-boot state but cannot fix those already affected.
    4. Administrators are advised to check update history for failed installs from December 2025 and avoid deploying KB5074109 on vulnerable devices.
    5. The boot failures in January result from a series of problematic updates, not just the KB5074109 patch alone.

    Microsoft has confirmed that the Windows 11 KB5074109 security update from January 2026 is not “randomly” causing healthy PCs to fail, but instead is triggering boot failures on devices that were already in an unstable state due to a problematic December 2025 update. When devices tried to install the December update, then rolled it back and continued to run on that flawed version, they are now more likely to experience a UNMOUNTABLE_BOOT_VOLUME (0xED) error and a black screen following the installation of KB5074109.

    Update Affects Limited Devices

    As per Microsoft, this issue impacts a small number of physical Windows 11 24H2 and 25H2 devices, primarily found in commercial settings, and does not seem to affect virtual machines. The company highlights that the January update is essentially “stacking” on top of the corrupted state caused by the December update, explaining why only some systems face boot loops while others can install KB5074109 without any problems.

    Ongoing Efforts for Resolution

    Microsoft is currently working on a partial fix that aims to stop more devices from entering a no-boot state once they are already in that compromised condition. However, this solution will not fix PCs that are already unable to boot, nor will it address the root cause of the December failure. Affected machines will still require manual recovery through the Windows Recovery Environment (WinRE) or external media to uninstall updates or repair the operating system.

    For the time being, the instructions remain the same: administrators should review the update history for failed installs from December 2025, refrain from deploying KB5074109 to vulnerable devices, and use WinRE for uninstalling or fully reinstalling the OS for systems that are currently stuck on the UNMOUNTABLE_BOOT_VOLUME screen.

    Continuing Challenges with Updates

    While this new explanation does not conclude the ongoing saga of Windows 11 updates, it does provide a clearer understanding that the boot failures seen in January are a result of a series of problematic updates rather than a single isolated patch.

     

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  • Windows 11 KB5074109 Drops Support for Older Modems

    Windows 11 KB5074109 Drops Support for Older Modems

    Key Takeaways

    1. The January 2026 Windows 11 KB5074109 security update causes crashes and boot issues on some PCs.
    2. The update removes four old modem drivers, making certain modems stop working.
    3. Many users have reported that their dial-up and telephony modems fail to operate after installing the update.
    4. Microsoft justifies the driver removal as a security measure to address unresolved kernel vulnerabilities.
    5. Users relying on affected modems have limited options: uninstall the update or upgrade to new hardware with supported drivers.

    Microsoft’s January 2026 Windows 11 KB5074109 security update has been causing issues on some PCs, leading to crashes and boot problems. Additionally, it’s intentionally disabling certain older modems.

    Driver Removals

    In the official changelog for KB5074109, Microsoft mentions a “Compatibility” change that eliminates four long-standing modem drivers from Windows 11: agrsm64.sys, agrsm.sys, smserl64.sys, and smserial.sys. The documentation clearly states that any modem hardware relying on these drivers will stop functioning after the update.

    Users Affected

    This situation has been frequently noted by users. After installing KB5074109, many find that their dial-up and telephony modems cease to operate, including some devices marketed as “Windows 11 compatible.” Rolling back the update immediately restores these modems, proving that the removal of the drivers is the cause of the problem.

    Microsoft’s Justification

    Both Microsoft and external analysts frame this action as a step towards enhancing security, rather than as an error. The drivers that were removed, which are utilized by older Agere/LSI and Motorola soft-modems, have been linked to unresolved vulnerabilities at the kernel level. Therefore, Microsoft opted to remove them from the operating system instead of continuing to distribute code that could be exploited.

    For users and small businesses that still depend on these modems for services like faxing, telemetry, or phone-logging, the options are quite limited. They can either uninstall KB5074109 and temporarily pause updates, or swap out the hardware for devices that utilize currently supported drivers. Microsoft’s own guidelines make it clear that there will not be any future support for modems associated with these four outdated drivers.

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  • Windows 11 KB5074109 Update Hurts Nvidia Gaming Performance

    Windows 11 KB5074109 Update Hurts Nvidia Gaming Performance

    Key Takeaways

    1. Performance Issues: KB5074109 is causing significant FPS drops (15–20) and game instability for some PC gamers using Nvidia GeForce GPUs on Windows 11 versions 24H2 and 25H2.

    2. Reported Problems: Users are experiencing increased microstuttering, short black-screen freezes, and occasional driver crashes during heavy gaming loads.

    3. Uninstall Solutions: Many gamers have resolved performance issues by uninstalling the update or restoring to a previous system image, with no official fix from Microsoft currently available.

    4. Nvidia’s Response: Nvidia has released a new Game Ready/hotfix driver that may help, but the most common user solution remains uninstalling the update.

    5. Lack of Acknowledgment: Microsoft has not officially recognized any gaming performance issues related to KB5074109, leaving gamers in a difficult position between security updates and maintaining gaming performance.

    Microsoft’s January 2026 Windows 11 KB5074109 security update seems to be causing troubles for some PC gamers, particularly those using Nvidia GeForce GPUs. This update brings 114 security fixes and various enhancements, but independent reports and discussions on forums are linking it to significant FPS drops and game instability on Windows 11 versions 24H2 and 25H2.

    Performance Issues Reported

    Users are saying they’ve experienced FPS drops of 15–20 in certain games after applying KB5074109. Additionally, they are facing issues like increased microstuttering, short black-screen freezes, and even occasional driver crashes when under heavy load. In many situations, the gaming experience only returns to normal after uninstalling the update or restoring a previous system image. Many sources, including MundoWin, Daily Game, and discussions in Nvidia GeForce Windows threads, highlight the same issue: while the update installs without a hitch, games that used to run smoothly now feel sluggish or less responsive on GeForce hardware.

    No Official Acknowledgment

    At this moment, Microsoft’s official documentation for KB5074109 does not mention any gaming performance issues, nor is there a specific hotfix targeting GeForce users. Nvidia has released a new Game Ready/hotfix driver that some gamers report is helpful, but the most common solution reported by users is to uninstall KB5074109 or revert to a previous restore point. After doing so, it is advised to pause Windows Update until a corrected build is made available by Microsoft. This situation leaves gamers with affected systems stuck between applying January’s security updates and regaining their full gaming performance.

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  • Windows 11 KB5074109 Update Causing Boot Failures

    Windows 11 KB5074109 Update Causing Boot Failures

    Key Takeaways

    1. Boot Failure Issue: The January 2026 Windows 11 security update KB5074109 has caused some computers to experience UNMOUNTABLE_BOOT_VOLUME errors, leading to complete boot failures.

    2. Limited Reports: The problem appears to affect a small percentage of devices running Windows 11 versions 24H2 and 25H2, as noted in community reports.

    3. Microsoft Investigation: Microsoft is investigating these boot issues but has not identified the exact cause or provided a hotfix yet.

    4. Recovery Recommendations: Users facing boot problems are advised to use the Windows Recovery Environment (WinRE) or external media to repair or revert their systems.

    5. Caution Advised: Users whose systems are functioning normally should remain calm, but system administrators may be more cautious with updates until a reliable solution is provided by Microsoft.

    Microsoft’s January 2026 Windows 11 security update KB5074109 has been associated with a significant problem beyond just crashes and application malfunctions: some computers are experiencing complete boot failures, displaying a UNMOUNTABLE_BOOT_VOLUME blue screen.

    Limited Reports of Boot Failures

    As noted in Microsoft’s internal status documents, which have been compiled by community sources like AskWoody, along with recent findings from BleepingComputer and Windows Central, there are “limited number of reports” indicating that Windows 11 devices running on version 24H2 and 25H2 encounter a UNMOUNTABLE_BOOT_VOLUME error after applying the January 13 security updates related to KB5074109.

    In these instances, the computers do not reach the login page, instead getting stuck in a loop that leads to a BSOD. This situation leaves users needing to recover their systems through the Windows Recovery Environment (WinRE) or by using external media.

    Ongoing Investigation by Microsoft

    Microsoft is currently looking into these boot issues and has stated that they appear to only impact a small percentage of devices. However, the company has not yet identified the precise cause of the UNMOUNTABLE_BOOT_VOLUME problem nor released a specific hotfix. Their public health pages primarily address issues like Remote Desktop failures, black screens, and crashes of cloud applications that are linked to KB5074109 and the January out-of-band updates.

    For now, Microsoft recommends that users facing the UNMOUNTABLE_BOOT_VOLUME issue follow the same steps as for other boot problems: utilize WinRE and standard recovery methods to either repair or revert the system. This involves booting from either the recovery environment or installation media, trying to repair the file system, and, when feasible, uninstalling the January security update before Windows starts.

    No Need for Alarm

    For those whose computers are still functioning properly after the KB5074109 update, there’s no reason to panic. However, this new stop-code problem highlights the vulnerability of the January Windows 11 update process. With emergency hotfixes, rollback issues, and now complete boot failures, many system administrators will approach KB5074109 with heightened caution until Microsoft provides a fully reliable cumulative update.

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  • Fix Windows 11 KB5074109 Uninstall Error 0x800f0905

    Fix Windows 11 KB5074109 Uninstall Error 0x800f0905

    Key Takeaways

    1. The January 2026 KB5074109 security update for Windows 11 is causing significant issues, including black screens, app crashes, and Outlook freezing.
    2. Users attempting to uninstall the update are facing a rollback failure with error 0x800f0905, which halts the process.
    3. Microsoft has not provided a specific fix for the uninstall failure, leading users to seek workarounds like using a System Restore point or a Windows Update repair installation.
    4. Ongoing issues include disrupted S3 sleep mode on older computers and persistent errors when launching apps, particularly with Outlook Classic.
    5. Microsoft acknowledges the problems with KB5074109 but advises users to wait for a resolution if their computer is functioning well.

    The Windows 11 KB5074109 security update from January 2026 is turning into a nightmare for many users. After Microsoft informed those impacted that it was okay to remove the update, which caused black screens, app crashes, and Outlook freezing, some are now experiencing issues where the rollback fails with error 0x800f0905.

    Uninstall Challenges

    As reported by Windows Central, users attempting to uninstall KB5074109 on their Windows 11 devices are encountering the 0x800f0905 error, which is related to the servicing stack or component store. This error completely halts the uninstall process, leaving users in a tough spot. They are forced to either hold on to a problematic update that disrupts apps and sleep mode or look for more extreme solutions.

    Workarounds and Recommendations

    At this moment, Microsoft has not provided a specific fix for the uninstall failure. Nevertheless, tech experts and support documents are suggesting a few potential workarounds. These include utilizing a System Restore point, if available from before the update, performing a “Fix problems using Windows Update” repair installation that retains apps and files, and then attempting to uninstall the update again. It’s important to remember the usual advice to create a complete backup before trying these methods.

    Ongoing Issues

    Meanwhile, reports of complications from KB5074109 keep piling up. Users with older computers are finding that the update disrupts S3 sleep mode, leading their screens to go blank without actually entering low-power sleep, which often necessitates a hard reboot. Others are still facing 0x803F8001 errors when launching apps, and Outlook Classic is freezing, particularly when mail archives are stored in OneDrive or other cloud locations.

    In the meantime, the situation remains chaotic: Microsoft still classifies KB5074109 as the official Windows 11 January 2026 security update and has acknowledged various regressions. They suggest uninstalling it if users are severely impacted, but some can’t even roll back smoothly without encountering yet another error. If your computer is functioning well, it might be best to wait patiently for a resolution.

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  • Windows 11 KB5074109 Update: Microsoft Recommends Rollback

    Windows 11 KB5074109 Update: Microsoft Recommends Rollback

    Key Takeaways

    1. Users are dissatisfied with the January 13, 2026, cumulative update (KB5074109) for Windows 11, reporting system instability and issues after installation.

    2. Complaints include black screens and display problems, especially for users with NVIDIA graphics hardware, leading some to revert to Safe Mode for uninstallation.

    3. Applications, including Windows tools and Outlook, are failing to open or displaying error codes, with specific issues noted for Outlook users with PST files in OneDrive.

    4. Microsoft released urgent out-of-band updates to address some issues, but reports of black screens and app-launch failures persist for Windows 11 versions 24H2 and 25H2.

    5. Experts recommend uninstalling the update if experiencing instability, while cautioning that reverting may increase security risks; users should stabilize their systems first before reapplying fixes.

    Microsoft’s January 13, 2026, cumulative update for Windows 11 has been met with increasing dissatisfaction from users. They claim their systems became unstable right after they installed it. The update, known as KB5074109, upgrades Windows 11 25H2 and 24H2 to OS builds 26200.7623 and 26100.7623 and incorporates security enhancements and reliability fixes, notably a power fix for devices equipped with a Neural Processing Unit (NPU).

    Uninstalling the Update

    As more complaints surfaced, Microsoft’s support guidance and public troubleshooting discussions began to suggest that uninstalling the update was an acceptable solution for those affected. Various Windows communities have reported multiple recurring issues linked to the January update, with some problems seemingly specific to certain setups.

    Several users have encountered unexpected black screens or display issues following the update installation, particularly among those using NVIDIA graphics hardware. In some serious instances, users were forced to revert to Safe Mode or the Windows recovery environment to uninstall the update and regain normal startup functionality.

    Application Issues

    Reports also indicated that applications would not open and displayed error codes like 0x803F8001. This included Windows applications such as Notepad and Snipping Tool, as well as third-party programs and software from vendors. Microsoft has recognized problems impacting “classic” Outlook since the January 13 updates. The company noted that users with POP account profiles, especially those with PST files that are stored in OneDrive, may experience Outlook freezing and failing to close properly, which can hinder the app from reopening correctly.

    For affected Outlook users, Microsoft has shared workarounds, including relocating PST files from OneDrive or utilizing different access methods until a permanent solution is provided.

    Emergency Updates

    Following Patch Tuesday, Microsoft released urgent out-of-band updates addressing specific regressions, including issues related to Remote Desktop sign-in failures and certain shutdown problems on Windows 11 23H2. Nevertheless, reports from users regarding black screens and app-launch failures on Windows 11 24H2 and 25H2 persist. Some users also mentioned issues with sleep and resume functionality on particular hardware. These power-state reports differ by device and setup, and Microsoft has not broadly confirmed them like it has with the Outlook POP/PST problem.

    If your PC is functioning properly after the January update, many experts recommend keeping it installed to benefit from the latest security fixes and protections included in the monthly release.

    If you noticed stability issues immediately after installing KB5074109, such as black screens, ongoing app failures, or hangs in Outlook Classic, uninstalling the update is now widely regarded as a temporary measure while Microsoft develops a more comprehensive solution. The typical removal process can be done through Settings, under Windows Update history, followed by a system restart. If the system fails to boot normally, the update can also be uninstalled from the Windows recovery environment.

    Microsoft and several security experts continue to caution that reverting a security update could heighten the risk of vulnerabilities. However, for users experiencing frequent crashes or unusable productivity applications, the practical advice has become clearer: stabilize your machine first, then reapply fixes when Microsoft releases a corrected version.

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  • Windows 11 January Patch Tuesday Causes Black Screen Issues

    Windows 11 January Patch Tuesday Causes Black Screen Issues

    Key Takeaways

    1. The January update for Windows 11 is causing a “black screen” issue on specific builds (24H2 and 25H2).
    2. The issue is not widespread but can be aggravated by certain software setups.
    3. Users experiencing the black screen can try various technical methods to restore functionality.
    4. Many users are exploring alternative operating systems like Zorin OS and Bazzite due to ongoing issues with Windows 11.
    5. It’s recommended to back up systems before updates and uninstall the KB5074109 package as a temporary fix until Microsoft releases a proper update.

    As seen in a report from Windows Latest, the January update is causing a “black screen” issue on certain computers. After booting up, the screen stays dark, even though the system may still be functioning in the background. This problem affects Windows 11 builds 24H2 (26100.7623) and 25H2 (26200.7623).

    Analysis of the Issue

    Experts have found that this issue is not widespread, but it can be made worse by certain software setups. There are two main areas that are thought to be the core of this problem.

    For those who are experiencing this black screen issue, there are a few technical methods that users can try to regain full functionality.

    Alternatives to Windows

    With the growing number of technical issues in Windows 11 and the upcoming end of support for Windows 10 in October 2026, many users are looking into alternative operating systems. Zorin OS 18, created by Artyom Zorin, has seen over two million downloads in just three months (refer to X post). Similarly, the Bazzite developers noted a rise of about 12,500 users in just a month (check X post).

    The current situation highlights the importance of a careful update approach for Windows 11. Systems that rely on modification tools should definitely have complete backups before applying any new patches. Until Microsoft issues a fixed update, uninstalling the KB5074109 package seems to be the most reliable temporary solution.

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