Windows 11 flaw locks C: drive access on some Samsung laptops
March 14, 2026
A widespread Windows 11 bug is preventing users from accessing their C: drive, with many encountering the error “C:\ is not accessible – Access denied.” The issue seems tied to a February 2026 security update (KB5077181) and is primarily affecting Samsung-made laptops.
What’s known so far
- The problem surfaced after the February 2026 update and appears to be more common on Samsung Galaxy Book devices.
- Some reports suggest the Samsung Share app could be related, though Microsoft has not confirmed a precise cause.
- The bug can block key operations, including opening files, launching programs, and performing administrative tasks; Office apps and web browsers are among the affected applications.
- Regions reported to be impacted include Brazil, Portugal, Korea, and India, with the latest Windows 11 versions 24H2 and 25H2 most affected.
What Microsoft is doing
- Microsoft says it is investigating the issue in collaboration with Samsung and will release updates when more information becomes available.
- Affected users may see the error during normal use, rendering the system largely unusable until the problem is resolved.
What you can do if you’re affected
- Roll back the update: Open Settings > Windows Update and follow the steps to uninstall the February 2026 update (KB5077181). You can also look for official rollback guidance from Microsoft.
- Pause further updates: If you have not yet installed the February 2026 patch, you can choose to pause updates to prevent new issues while a fix is developed.
- Caution with workarounds: Some Reddit threads suggest changing the ownership of the C: drive as a workaround. This approach can carry data-loss or security risks, so proceed with caution and ensure you have current backups if you attempt it.
Notes for affected users
- The problem seems limited to certain Windows 11 builds (notably 24H2 and 25H2) and does not appear to be a universal defect across all devices.
- If you rely on a Samsung Galaxy Book or other Samsung-branded laptops, monitor Microsoft and Samsung support channels for any official advisories or hotfixes.
Bottom line
- A targeted bug linked to a February 2026 Windows 11 update is causing C: drive access errors on some Samsung laptops.
- Microsoft and Samsung are investigating, with a fix expected to come via updates. In the meantime, options include rolling back the problematic update or pausing future updates, while avoiding risky manual fixes without proper backups.