A recent Windows 11 update has caused significant issues for Samsung Galaxy Book owners, leading to the loss of access to the crucial C drive. Users have encountered an error message stating “C:is not accessible – Access denied,” preventing them from opening files and using various applications like Microsoft Outlook, Office apps, and specific web browsers.
Several model numbers, including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA, are believed to be affected by this issue.
Microsoft has acknowledged the problem, attributing it to the February 2026 security update (KB5077181) and subsequent updates. The error restricts file access and application launches, affecting routine actions like file access, application launches, and administrative tasks without requiring specific user actions. Users have also faced challenges in elevating privileges, uninstalling updates, and collecting logs due to permission failures.
The root cause of the problem is suspected to be the Galaxy Connect app by Samsung, which facilitates tasks like screen mirroring, file sharing, and data transfer between Galaxy smartphones and Windows PCs. The app has been temporarily removed from the Microsoft Store to prevent further installations while a fix is being developed.
Samsung has republished a stable previous version of the app to prevent additional devices from being affected. Recovery options for already impacted devices are limited, with ongoing evaluations for remediation in collaboration with Microsoft.
While the timeline for a fix remains uncertain, Samsung PC owners are advised to hold off on updating to Windows 11 versions 24H2 and 25H2. Users currently on these versions should refrain from updating further until the issue is resolved.