Trending Now - Windows 11 Users Report C: Drive Access Issues on Samsung Pcs

WHO:

Microsoft is investigating the issue.

Samsung is involved in determining the cause of the problem.

A Reddit user claiming to be a Samsung technician in Brazil has posted a workaround.

WHAT:

Windows 11 users are experiencing access issues with their C:\ drive after installing the February 2026 security updates.

Users encounter the error message, "C:\ is not accessible – Access denied."

The issue affects the ability to launch applications including Outlook, Office apps, web browsers, system utilities, and Quick Assist.

The problem primarily impacts Samsung Galaxy Book 4 and other Samsung consumer devices.

The issue is reported to be related to Windows 11 version 25H2 and 24H2.

A workaround involves changing the ownership of the entire C:\ drive to the "Everyone" group, which is risky and weakens security.

WHERE:

The issue has been reported mostly in Brazil, Portugal, South Korea, and India.

WHEN:

The February 2026 security updates were installed, leading to the reported issues.

The specific update causing the issue is identified as KB5077181.

WHY:

Microsoft suspects the issue may be related to the Samsung Share application, though the exact cause is unconfirmed.

HOW:

Users experience the issue during normal Windows usage, such as accessing files, launching applications, or performing administrative tasks.

Microsoft is working with Samsung to investigate the problem and determine its root cause.

(UPDATED March 14, 2026 19:10 UTC)

Microsoft is currently investigating access issues that Windows 11 users are facing with their C:\ drive after installing the February 2026 security updates, specifically update KB5077181. The problem, which primarily affects Samsung Galaxy Book 4 and other Samsung devices, results in an error message stating "C:\ is not accessible – Access denied," disrupting the launch of various applications. A workaround has been suggested by a Reddit user claiming to be a Samsung technician in Brazil, which involves changing the ownership of the C:\ drive to the "Everyone" group, although this poses security risks.