In the latest security update for Windows 11, identified as KB5083769, a notable change has been introduced with the psmounterex.sys driver. This alteration has led to compatibility issues with various third-party backup solutions. Microsoft has clarified that this is not a bug within the operating system but rather a necessary adjustment to enhance overall security. Users are encouraged to ensure their backup software is updated accordingly.
Released on April 14, 2026, the “2026-04 Security Update (KB5083769) (Build 26200.8246)” not only brings new features and improvements but also implements a significant security measure by adding known “vulnerable kernel drivers” to a blocklist. This proactive approach aims to fortify system defenses against potential threats, affecting popular backup solutions such as Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup across Windows 11, 10, and Windows Server.
How to check if a driver is blocked
For users wishing to verify whether a specific driver has been blocked, Bleeping Computer provides a straightforward method using the Event Viewer. Follow these steps:
- Open the Event Viewer.
- Navigate to Applications and Services Logs > Microsoft > Windows > CodeIntegrity > Operational.
- In the event’s view, locate the “Event ID 3077” associated with “Policy ID {D2BDA982-CCF6-4344-AC5B-0B44427B6816}”.
If this entry is present, it confirms that the driver has indeed been added to the system’s blocklist.
Windows Central’s Take
While the rationale behind blocking vulnerable drivers is understandable, it raises concerns about the unintended consequences of such updates. The decision prioritizes security, which is commendable; however, the disruption of critical backup tools can pose significant challenges for users. It is advisable for those relying on third-party backup solutions to proceed with caution. Before installing the update, ensure that your backup software is fully updated and verify that all scheduled jobs are functioning correctly.
This scenario reflects a recurring theme with updates: security enhancements take precedence, while compatibility issues are often addressed subsequently. Although this strategy may benefit users in the long run, it places an increased burden on them to remain vigilant regarding their tools and software.
Have you encountered this issue on your PC? Feel free to share your experiences in the comments.
More resources
For further insights, explore comprehensive how-to guides, troubleshooting advice, and essential tips designed to help you maximize your experience with Windows 11 and 10. Start browsing here:
Join us on Reddit at r/WindowsCentral to share your insights and discuss our latest news, reviews, and more.
My Windows 11 backup broke after KB5083769 — Microsoft says this simple fix might save your files
In the latest security update for Windows 11, identified as KB5083769, a notable change has been introduced with the psmounterex.sys driver. This alteration has led to compatibility issues with various third-party backup solutions. Microsoft has clarified that this is not a bug within the operating system but rather a necessary adjustment to enhance overall security. Users are encouraged to ensure their backup software is updated accordingly.
Released on April 14, 2026, the “2026-04 Security Update (KB5083769) (Build 26200.8246)” not only brings new features and improvements but also implements a significant security measure by adding known “vulnerable kernel drivers” to a blocklist. This proactive approach aims to fortify system defenses against potential threats, affecting popular backup solutions such as Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup across Windows 11, 10, and Windows Server.
How to check if a driver is blocked
For users wishing to verify whether a specific driver has been blocked, Bleeping Computer provides a straightforward method using the Event Viewer. Follow these steps:
If this entry is present, it confirms that the driver has indeed been added to the system’s blocklist.
Windows Central’s Take
While the rationale behind blocking vulnerable drivers is understandable, it raises concerns about the unintended consequences of such updates. The decision prioritizes security, which is commendable; however, the disruption of critical backup tools can pose significant challenges for users. It is advisable for those relying on third-party backup solutions to proceed with caution. Before installing the update, ensure that your backup software is fully updated and verify that all scheduled jobs are functioning correctly.
This scenario reflects a recurring theme with updates: security enhancements take precedence, while compatibility issues are often addressed subsequently. Although this strategy may benefit users in the long run, it places an increased burden on them to remain vigilant regarding their tools and software.
Have you encountered this issue on your PC? Feel free to share your experiences in the comments.
More resources
For further insights, explore comprehensive how-to guides, troubleshooting advice, and essential tips designed to help you maximize your experience with Windows 11 and 10. Start browsing here:
Join us on Reddit at r/WindowsCentral to share your insights and discuss our latest news, reviews, and more.