How to fix Samsung PC drive C is not accessible (access denied) on Windows 11

A critical issue on Windows 11 causes loss of access to the “C” drive on select Samsung devices.
The error C:\ is not accessible – Access denied blocks files and apps like Outlook, Office, browsers, and system tools.
Affected systems include Samsung Galaxy Book 4 laptops and desktops running versions 24H2 and 25H2.
The issue is not caused by Windows updates KB5077181 or KB5079473. Instead, it’s a conflict with the Samsung Galaxy Connect and Continuity Service apps that affects system permissions.

On Windows 11, after installing updates KB5077181 or KB5079473, Microsoft has received reports of a critical issue affecting select Samsung devices, in which users may suddenly lose access to the system drive.

The problem triggers the error C:\ is not accessible – Access denied, effectively locking users out of their files and preventing many essential apps from launching, including Outlook, Office apps, web browsers, system tools, and Quick Assist.

According to the company, the issue has been reported on several Samsung Galaxy Book 4 laptops and Samsung desktop models running Windows 11 24H2 and 25H2. Although the problem surfaced around the February 2026 security update (KB5077181) and subsequent releases, Microsoft confirmed that the system updates are not the root cause.

Instead, Microsoft has confirmed that the problem is a conflict with the Samsung Galaxy Connect app, which can interfere with system permissions and block access to the “C:” drive during normal usage.

Affected users may encounter the issue during routine tasks such as opening files, launching apps, or performing administrative actions. In more severe cases, the problem can also prevent privilege elevation, update uninstallation, or even the collection of diagnostic logs due to persistent permission failures.

Thankfully, the company is offering a workaround to resolve this issue that involves uninstalling the Samsung app and manually changing system permissions.

In this guide, I’ll outline steps to resolve drive issues on Samsung PCs after installing the cumulative updates KB5077181 or KB5079473 on Windows 11.

Recovery steps for Samsung PCs causing drive access loss on Windows 11

If you have a Samsung device using the Galaxy Connect or Continuity Service apps, causing loss of access to the “C” drive, while on the desktop, follow these steps:

Open Settings on Windows 11.
Click on Apps.
Click the Installed apps page.
Select the Samsung Galaxy Connect (or Samsung Continuity Service) app.
Click the menu button on the right and choose the Uninstall option.
Restart the computer.
Open File Explorer.
Click on This PC.
Right-click the Local Disk (C:) and select Properties.
Click the Security app.
Click the Advanced button.
Click the Change button next to the “Owner” field.
Confirm the Everyone object name.
Click the OK button.
Click the Yes button.
Click the Security app.
Click the Edit button.
Confirm the Everyone object name.
Click the OK button.
Click the Yes button.
Use “Alt + C” to continue if you notice multiple security alerts.
Open the Notepad app.

Copy and paste the following code:

BAT 
icacls c:\ /grant BUILTIN\Administrators:(OI)(CI)(F) 
icacls c:\ /grant "NT AUTHORITY\SYSTEM:(OI)(CI)(F)" 
icacls c:\ /grant BUILTIN\Users:(OI)(CI)(RX) 
icacls c:\ /grant "NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(M)" 
icacls c:\ /grant "NT AUTHORITY\Authenticated Users:(AD)" 
icacls c:\ /setowner "NT Service\TrustedInstaller" 
icacls c:\ /remove everyone 
pause 
Show more lines

Click on File and choose the Save as button.
Set the Save as type to All Files.
Confirm the RestoreAccess.bat name in the file.
Save the file to the desktop.
Right-click the newly created files and choose the Run as Administrator option.
Click the Yes button.
Restart the computer.

Once you complete the steps, the installation drive (C) should open normally, the system should operate normally, and the drive ownership should be restored to “TrustedInstaller.”