Microsoft says Samsung Galaxy Connect caused Windows 11 C: drive lockouts on Galaxy Book 4 PCs
Microsoft has confirmed that recent reports of Samsung PCs losing access to the C: drive were not caused by Windows monthly updates. In its Windows Release Health dashboard, the company says the issue was traced to the Samsung Galaxy Connect app after reports linked the problem to devices running Windows 11 24H2 and 25H2.
Affected systems can show the error “ C: is not accessible, Access denied ,” which blocks file access and can stop apps from launching. Microsoft says the failures can affect Outlook, Office apps, web browsers, system tools and Quick Assist, and in some cases users also cannot elevate privileges, uninstall updates, or collect logs because of broken permissions.
Source: Microsoft
The company says the issue has been observed on Samsung Galaxy Book 4 laptops and Samsung desktop models, including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA. Microsoft opened the issue on March 13 and marked it resolved externally on March 16, after concluding with Samsung that the bug was tied to Galaxy Connect rather than the February KB5077181 update or later Windows patches. According to Windows Latest, also said early complaints appeared before March Patch Tuesday, which helped separate the issue from Windows Update itself.
Microsoft says mitigations were deployed starting March 14. As part of that response, the affected Galaxy Connect app was temporarily removed from the Microsoft Store, while Samsung republished an older stable version to stop additional systems from being hit.
For already affected devices, Microsoft has published a recovery article that points users to uninstall Samsung Galaxy Connect or Samsung Continuity Service and then restore default C: drive permissions. The company says Samsung and Microsoft validated those steps together, and the fix should return normal access without modifying personal files.
Source: Windows 11 Known Issues , Windows Latest
