"Access denied" errors on your C with Samsung laptop (Galaxy Book4)

Question

I am using a Samsung laptop (Galaxy Book4) and recently installed the KB5079473 and KB5077181 update, after that I am not able to access C drive, also Microsoft word, excel etc not opening.
Uninstall and Install options also not working now.

Answer 1

Hi, good day!

Please try this if it helps.

Make sure you sign-in using a Windows account with Administrator privileges

Open File Explorer > Right click on C: drive

Select Properties > Security > Advanced > Change

On the text box, type Everyone

Click Check Names

Tick the option to replace the owner on subcontainers and objects

Click Change and type and select the "Everyone" option again

Click OK and Apply

When prompted for any warning messages, just click Enter to continue with the process until the full scan of your C drive is complete

Once finish, restart your computer

Delete any files from the recycle bin if prompted.

I look forward to receiving your update and I'm willing to collaborate with you till we resolve the issue. Do keep me informed by clicking "Add comment" below.

Answer 2

The issue matches a known problem affecting some Samsung Galaxy Book 4 and Samsung Desktop models after installing KB5077181 and later updates on Windows 11 24H2/25H2. Symptoms include:

• “C:\ is not accessible – Access denied”
• Inability to open apps such as Outlook, Office apps, web browsers, system utilities, and Quick Assist
• Inability in some cases to elevate privileges, uninstall updates, or collect logs

Cause:

• The problem is caused by an issue in the Samsung Galaxy Connect app, not by the Windows updates themselves.
• It affects specific Samsung models, including Galaxy Book 4 devices, running Windows 11 versions 24H2 and 25H2.

Current status and mitigation:

• The affected Samsung Galaxy Connect app version has been temporarily removed from Microsoft Store to prevent new installs.
• Samsung has republished a stable previous version of Samsung Galaxy Connect to stop the issue from recurring on additional devices.
• Recovery options for devices that are already impacted are currently limited.
• Samsung is continuing to evaluate remediation approaches with Microsoft’s support.

What to do next:

1. Check whether Samsung Galaxy Connect is installed on the device.
2. If the device is already impacted (C: drive inaccessible, apps not opening, cannot uninstall updates), standard actions such as uninstalling updates or repairing Office are likely to fail due to permission issues.
3. Monitor Samsung and Microsoft channels (for example, Samsung support and Windows 11 24H2/25H2 release health pages) for updated remediation guidance, as both companies are actively investigating and working on recovery options for affected devices.

Because recovery options are limited at this time for already-affected devices, remediation may require vendor-guided steps or service from Samsung once they publish a supported fix.

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References:

• Windows 11, version 25H2 known issues and notifications
• Windows 11, version 24H2 known issues and notifications