Windows 11 Bug Locks Users Out of C: Drive

A significant bug affecting Windows 11 has emerged, primarily impacting users of Samsung laptops. This issue prevents access to the C: drive, displaying the error message "C:\ is not accessible – Access denied." The problem appears to have been introduced with the February 2026 security update (KB5077181) and has been exacerbated by the March 2026 update (KB5079473). Microsoft is actively investigating the matter and collaborating with Samsung to develop a solution.

TechRadarWindows 11 March Update Blocks C:\ Drive Access for Some UsersWindows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

The bug predominantly affects Samsung Galaxy Book models, including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA. Reports indicate that users from multiple regions, including Brazil, Portugal, Korea, and India, are experiencing these issues. The bug has rendered many applications, including Office apps and web browsers, unusable for affected users.

Windows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

Microsoft has acknowledged the problem, stating that it is "presently investigating" the bug and will provide updates as more information becomes available. The company has suggested that the issue may be linked to the Samsung Galaxy Connect app, which facilitates connections to smart devices. However, it has clarified that the C: drive access issue is not directly caused by the Windows updates themselves, but rather by a bug in the Galaxy Connect app.

Windows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

Despite Microsoft's reassurances, some users remain skeptical about the company's handling of the situation. Critics argue that the timing of the updates and the subsequent issues have damaged Microsoft's reputation, which is already under scrutiny. Some reports suggest that the problems may be more widespread than Microsoft acknowledges, with users experiencing system freezes and random reboots.

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There is a discrepancy in the reporting of the severity of the issues caused by the March 2026 update. While some sources claim that the update has led to significant system problems, including BSODs and freezing, others, such as Windows Latest, assert that these claims are exaggerated and based on a limited number of user complaints. Microsoft has stated that the March update is not responsible for these issues, attributing them instead to the Galaxy Connect app.

Windows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

• “While the reports coincided with recent March Patch Tuesday timing, investigation confirmed the issue is not caused by current or previous Windows monthly updates,” — Microsoft

Windows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

• “Microsoft’s investigation later found that the C drive becomes locked and permission is denied on some PCs because of a bug in the Samsung Galaxy Connect app.” — Microsoft

Windows 11 KB5079473 is not causing BSODs or an inaccessible C: drive and app failures, says Microsoft

As Microsoft and Samsung work together to resolve the issue, users are advised to consider rolling back the recent updates or pausing them if they have not yet been installed. Further updates from Microsoft are anticipated as the investigation continues.

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