Some Samsung Galaxy Book owners are experiencing significant issues following a recent Windows 11 update. The update seems to have led to critical problems, including the loss of access to the C drive, with affected users encountering an error message stating “C: is not accessible – Access denied.”
This access blockage is preventing users from opening files and running certain applications like Microsoft Outlook, Office apps, and specific web browsers. The problem seems to be affecting models with the following numbers: NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA.
Microsoft has acknowledged the issue, stating that some Samsung device models are losing access to the C: drive after installing the February 2026 security update (KB5077181) and subsequent updates. Users are encountering the error message “C: is not accessible – Access denied,” which is hindering access to files and impeding the launch of various applications, including Outlook, Office apps, web browsers, system utilities, and Quick Assist.
The problem appears to be linked to Samsung’s Galaxy Connect app, which enables functions like screen mirroring, file sharing, and data transfer between Galaxy smartphones and Windows PCs. The app has been temporarily removed from the Windows app store while a solution is being developed.
Microsoft mentioned that the affected Samsung Galaxy Connect application was taken down from the Microsoft Store to prevent further installations, and Samsung has reissued a stable previous version of the app to prevent additional devices from being affected. Recovery options for impacted devices are limited, and Samsung is working with Microsoft to explore potential solutions.
The timeline for a fix is uncertain at this point. For Samsung PC owners who have not yet updated to Windows 11 versions 24H2 and 25H2, it is advisable to hold off on updating. Those currently using Windows 11 versions 24H2 and 25H2 are advised to refrain from making any changes.