When dealing with Windows Update temporary folders (typically those GUID-named directories in C:\), even experienced administrators encounter this paradox: You have ownership, you've set full control permissions recursively, yet Windows still demands "permission from yourself" to delete the folder.

The root cause lies in Windows' multiple permission layers and inheritance quirks. Here's what actually happens:

// Example of checking effective permissions via PowerShell
$path = "C:\\Windows.old"
$acl = Get-Acl $path
$acl.Access | Format-Table IdentityReference, FileSystemRights, AccessControlType, IsInherited -AutoSize

Common hidden culprits include:

• Broken permission inheritance chains
• Mandatory Integrity Control (MIC) blocking operations
• Object Manager namespace conflicts
• Pending file operations from Windows Modules Installer

Solution 1: Using PowerShell with -Force and -Recurse

Remove-Item -Path "C:\\{GUID_Folder}" -Force -Recurse
# If that fails, try combining with Take-Ownership
takeown /F "C:\\{GUID_Folder}" /R /D Y
icacls "C:\\{GUID_Folder}" /grant Administrators:F /T /C /Q

Solution 2: Leveraging Process Explorer

1. Download Sysinternals Process Explorer
2. Search for handles to the problematic folder (Ctrl+F)
3. Close any processes holding handles

For stubborn cases, boot into WinPE or Safe Mode and attempt deletion. Alternatively, use this C# snippet to force removal:

using System.IO;
using Microsoft.Win32.SafeHandles;

static void ForceDelete(string path)
{
    var di = new DirectoryInfo(path) { Attributes = FileAttributes.Normal };
    foreach (var info in di.GetFileSystemInfos("*", SearchOption.AllDirectories))
    {
        info.Attributes = FileAttributes.Normal;
    }
    di.Delete(true);
}

Windows implements several overlapping security mechanisms:

Many Windows administrators and power users encounter this frustrating scenario: you've explicitly taken ownership of a folder, granted yourself full control permissions (including all child objects), yet Windows still demands "administrator permission" when attempting deletion. This is particularly common with Windows Update temporary folders (identifiable by their GUID-style names) left in the root directory.

Windows' permission system has several layers that interact in non-obvious ways:

1. Explicit permissions (what you see in Security tab)
2. Inherited permissions (from parent objects)
3. Mandatory Integrity Control (MIC) levels
4. File/folder locks (handle-based restrictions)
5. System-protected status flags

Before proceeding with solutions, verify these potential issues:

// Check file handles using PowerShell
Get-Process | foreach { 
    $process = $_
    $_.Modules | where { 
        $_.FileName -like "C:\\Windows\\Temp\\*" 
    } | select @{n="Process";e={$process.Name}}
}

// Verify MIC levels using icacls
icacls "C:\\problem_folder" /verify

Many system folders are originally owned by the NT SERVICE\TrustedInstaller account. Even after changing ownership, residual protection might remain. Try this sequence:

takeown /f "C:\\target_folder" /r /d y
icacls "C:\\target_folder" /grant Administrators:(F) /t /c /q
icacls "C:\\target_folder" /setowner "Administrators" /t /c /q

When all permissions appear correct but deletion still fails, consider these approaches:

# Method 1: Boot into Safe Mode
bcdedit /set {current} safeboot minimal
shutdown /r /t 0

# Method 2: Use native Windows tools
taskkill /f /im explorer.exe
del /f /q "problem_folder"
start explorer.exe

# Method 3: PowerShell nuclear option
Start-Process powershell -Verb runAs -ArgumentList @"
Remove-Item -Path 'C:\\target' -Recurse -Force
"@

For system-protected folders, you might need to modify these registry keys (backup first!):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate]
"SuspendService"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TrustedInstaller]
"Start"=dword:00000004

When standard methods fail, these often succeed:

:: Robocopy mirror trick
robocopy "C:\\empty_dir" "C:\\target_folder" /mir

:: Using subst to change path context
subst X: "C:\\"
rd /s /q X:\\target_folder
subst X: /d

:: Create scheduled task for deletion
schtasks /create /tn "DeleteTask" /tr "cmd /c rmdir /s /q 
'C:\\target_folder'" /sc once /st 00:00 /ru SYSTEM
schtasks /run /tn "DeleteTask"