A Windows 11 bug introduced by a recent update is blocking access to the C: drive on certain Samsung PCs, displaying an "Access Denied" error message directly in File Explorer. Both versions 24H2 and 25H2 are affected. Microsoft is investigating, but no official fix is available yet.
The bug has been surfacing for a few days now, and its impact goes well beyond a simple inconvenience. Users running Windows 11 on Samsung hardware are finding themselves locked out of their primary drive, the C: drive, with a blunt error message: "C:\ is not accessible: Access denied." And the problem doesn't stop at File Explorer.
Any application that needs to read from the system drive, any administrative task that touches the disk, triggers the same wall. The machine is technically running, but practically crippled.
The C: drive access bug hits Samsung PCs specifically
What makes this bug particularly frustrating is how targeted it appears to be. So far, only Samsung devices are confirmed affected. No other hardware manufacturers have been reported in the same situation, which immediately points toward a software conflict tied to Samsung-specific components or software layers rather than a universal Windows flaw.
Quick Share under suspicion
Microsoft, headquartered in Redmond, is actively investigating the issue. The current suspicion points to Quick Share, Samsung's file-sharing feature deeply integrated into its Windows devices. The theory is that a conflict between Quick Share and the latest Windows update is corrupting or overriding the security permissions applied to the C: drive, effectively locking out the system's own users.
Quick Share is a wireless file-transfer feature developed by Samsung and Google, integrated into Samsung PCs running Windows. It allows nearby devices to exchange files without cables or cloud services.
Both 24H2 and 25H2 are in the firing line
The bug affects two active branches of Windows 11: versions 24H2 and 25H2. That's a significant portion of the active Windows 11 install base on Samsung hardware, covering both users on the stable release and those on the more recent preview builds. Microsoft has not narrowed the issue to a single update package, and no specific KB number has been publicly identified as the culprit.
The only available fix comes with a serious security trade-off
With no official patch from Microsoft, a temporary workaround has been circulating on Reddit, credited to an anonymous community member. The fix involves modifying the security permissions of the C: drive and granting access to "Everyone."
Concrètement, this means opening the drive's Properties menu, navigating to the Security tab, and manually adding "Everyone" as a user group with full access rights. The operation itself is straightforward for anyone comfortable in Windows settings. But the implications are not trivial.
Setting C: drive permissions to “Everyone” weakens the security of the entire system. Any user account or process on the machine gains elevated access to system files. Apply this workaround with caution and only if the bug is actively disrupting your workflow.
Granting "Everyone" access to the root system drive effectively removes a foundational layer of Windows security architecture. In a single-user home environment with no sensitive data, the risk may feel manageable. But on a professional machine, a shared device, or any PC connected to a corporate network, this is a meaningful exposure. Malicious software, rogue processes, or even a second local user account would gain access to the entire drive structure without restriction.
- Restores access to the C: drive in File Explorer
- Unblocks applications that require disk access
- Allows administrative tasks to run normally again
- Weakens system-wide security permissions
- Grants all user accounts and processes unrestricted C: drive access
- Not a permanent fix — Microsoft’s update may reset permissions again
Microsoft is investigating but has no timeline for a fix
The situation as of March 16, 2026 is that Microsoft acknowledges the problem and is working on a resolution. But "investigating" is a long way from "fixed." There is no patch, no rollback guidance, and no official workaround published by Microsoft itself. The company has not confirmed the Quick Share conflict theory publicly, though it remains the most credible hypothesis given the Samsung-exclusive scope of the bug.
For affected users, the options are limited. Waiting for Microsoft to push a corrective update is the cleanest path, but it leaves machines either locked out of their C: drive or running with degraded security permissions in the meantime. The Reddit workaround restores functionality, but it does so by dismantling a core security boundary that Windows 11 maintains by design. Anyone choosing to apply it should treat it as a temporary measure and revert the permissions as soon as an official fix lands, whether through a Windows Update patch or a targeted correction from Samsung addressing the Quick Share conflict directly.
