KB5077181 crash

Question

After the KB50 77181 update, I lost access to drive C.

Answer 1

Hi, good day!

• Are you using a Samsung laptop?
• When was the last time it worked properly?

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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

KB5077181 is a Windows 11 cumulative update. If access to drive C: is lost after installing it, the situation matches known cases where the update or its side effects cause serious system issues (for example, loss of Bluetooth or other core functionality) and may require offline servicing or rollback.

Because drive C: is the system volume, direct access problems usually mean either:

• File system or permissions corruption, or
• A problem introduced by the update that prevents normal boot or access.

From the available information, there are two practical paths:

1. Try to repair or roll back the update offline
   • Boot into Windows Recovery Environment (WinRE) from installation media or advanced startup.
   • Use DISM to remove or reapply packages if needed. For KB5077181, the documented servicing method is:
     • Place the MSU packages for KB5077181 in a folder (for example, C:\packages) on accessible media.
     • From an elevated command prompt in WinRE, run:

              DISM /Image:mountdir /Add-Package /PackagePath:Windows11.0-KB5077181-x64.msu
       

       replacing mountdir and the MSU path with the actual offline Windows path and package file.
   • If the system is still bootable but unstable, the same DISM pattern can be used online:

          DISM /Online /Add-Package /PackagePath:c:\packages\Windows11.0-KB5077181-x64.msu
     

   • If a newer servicing stack or prerequisite package is involved (as with KB5043080 + KB5077181), ensure they are applied in the documented order when servicing offline.
2. If repair is not feasible, perform an in-place repair or reinstall
   • If WinRE and DISM-based repair do not restore access to C:, use Windows 11 installation media to perform a repair install (keeping files if possible) or a clean installation.
   • Before a clean install, back up any accessible data from C: using WinRE or another machine.

If the system is still bootable but only C:\ root is inaccessible with “Access is denied”, check ownership and permissions from a parallel OS or WinRE and reset them to the appropriate account or Administrators, similar to the documented workaround for drive-root access issues after HomeGroup changes.

For severe or persistent issues directly tied to KB5077181 where rollback is unavailable and local repair fails, contact Microsoft Support and reference the KB number and symptoms.

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References:

• February 10, 2026—KB5077181 (OS Builds 26200.7840 and 26100.7840)
• Error message when you try to access the root of a drive after you leave HomeGroup in Windows 7 Release Candidate: "Access is denied."
• KB5077181 broke Bluetooth - Microsoft Q&A