Fix: New Windows bug breaks Samsung PCs, blocking access to C: drive

Windows 11 updates have caused all kinds of high blood pressure problems over the past few months. This trend continues with the latest February update, with Samsung PCs now experiencing serious issues after installing update KB5077181.

Confirmed by Microsoft as a known issue in Windows 11, the Samsung Galaxy Connect app is causing “loss of access to C: drive and application crashes” on Samsung PCs running Windows 11 25H2 or 24H2. Without access to the C: drive, PCs are effectively unusable. Microsoft and Samsung have released a workaround, but it will take some time.

Microsoft has reportedly received reports (like this one and this one) that some Samsung devices are losing access to the C: drive after installing Microsoft’s February Update as well as some subsequent updates. Affected users see the error message “C:\ is not accessible — Access Denied”. Access to files is blocked and some applications are blocked from launching, including Outlook, Office applications, web browsers, system utilities, and Quick Assist.

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Windows PCs from manufacturers other than Samsung are not affected.

Which Samsung devices are affected?

Initially, Microsoft’s February patches were suspected. However, further investigation by Microsoft and Samsung revealed that the Samsung Galaxy Connect app was causing the problem.

Microsoft writes:

Although the reports coincide with the recent March Patch Tuesday, the investigation confirmed that the issue is not caused by current or previous monthly Windows updates. The issue was observed on Samsung Galaxy Book 4 and Samsung Desktop models running Windows 11, versions 24H2 and 25H2, including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA.

Regarding how users experience the problem:

Affected devices experience this issue when users perform common actions, such as accessing files, launching applications, or performing administrative tasks, and do not require any specific user actions beyond routine operations. In some cases, users also cannot elevate their privileges, uninstall updates, or collect logs due to authorization failures.

There is a fix

Microsoft has temporarily removed the affected Samsung Galaxy Connect app from the Microsoft Store to prevent further installations. Samsung has since re-released a previous stable version of the app, which should mean no further issues should arise when installing the Samsung Galaxy Connect app (for new users).

However, for those who have already installed the faulty version of the Samsung Galaxy Connect app and are experiencing the issues described above, the problems still persist. However, there is a solution.

Microsoft claims that the recovery process will take approximately fifteen minutes. The workaround for the problem requires deleting the Samsung app, then asking Windows to repair the drive’s permissions and assign a new owner, then restoring Windows permissions to default, including applying fixes to some custom code written by Microsoft.

This story was updated by Mark Hachman on March 17 with details of the workaround.