A recent Windows 11 update has caused significant issues for Samsung Galaxy Book owners, leading to a loss of access to the crucial C drive. Users have been encountering an error message stating “C: is not accessible – Access denied,” preventing them from opening files and using key applications like Microsoft Outlook and various web browsers.
The problem seems to affect specific model numbers including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA. Microsoft has acknowledged the issue, linking it to the February 2026 security update (KB5077181) and subsequent updates.
The root cause of the issue is believed to be the Galaxy Connect app by Samsung, which facilitates functions like screen mirroring and file sharing between Galaxy smartphones and Windows PCs. The app has been temporarily removed from the Windows app store as a solution is being developed.
While the timeline for a fix remains uncertain, Samsung advises users with affected devices to refrain from updating to Windows 11 versions 24H2 and 25H2. Those already on these versions should avoid making any changes until a resolution is implemented. Recovery options for impacted devices are limited at the moment, and Samsung is collaborating with Microsoft to address the issue effectively.