A serious glitch in Windows 11 now prevents numerous users from accessing their main C: drive, rendering systems nearly unusable. Microsoft confirms the issue stems from the February 2026 security update (KB5077181) and collaborates with Samsung on a resolution.
Symptoms of the C: Drive Access Bug
Affected users encounter the error “C: is not accessible – Access denied” when attempting to open files, launch apps, or run admin tasks. Programs like Office applications and web browsers fail to operate properly due to restricted drive access.
Microsoft notes the problem likely ties to the Samsung Share app on laptops from Samsung, though investigations continue.
Affected Systems and Regions
The bug strikes Windows 11 versions 24H2 and 25H2, with widespread reports Brazil, Portugal, Korea, and India. Samsung laptops face the brunt of this disruption.
Immediate Fixes and Workarounds
To regain access, roll back the recent update via Settings > Windows Update. Microsoft provides step-by-step guidance on its support site.
Those without the update installed should pause future downloads in the same menu to avoid the issue.
Community-suggested fixes include modifying C: drive ownership settings, which succeed for some but pose risks to system stability—approach with care.
Microsoft actively probes the cause with Samsung and promises patches as details emerge. Stay updated through Windows Update for official remedies.
