PowerShell Change owner of files and folders

After a week of playing around with PowerShell, I found the answer to my own question:

$Target = "\\domain.net\myFolder"
$TempFolder = 'C:\TempFolder'
$TempFile = 'C:\TempFile'

#region Load super powers
$AdjustTokenPrivileges = @"
using System;
using System.Runtime.InteropServices;

 public class TokenManipulator
 {
  [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
  internal static extern bool AdjustTokenPrivileges(IntPtr htok, bool disall,
  ref TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen);
  [DllImport("kernel32.dll", ExactSpelling = true)]
  internal static extern IntPtr GetCurrentProcess();
  [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
  internal static extern bool OpenProcessToken(IntPtr h, int acc, ref IntPtr
  phtok);
  [DllImport("advapi32.dll", SetLastError = true)]
  internal static extern bool LookupPrivilegeValue(string host, string name,
  ref long pluid);
  [StructLayout(LayoutKind.Sequential, Pack = 1)]
  internal struct TokPriv1Luid
  {
   public int Count;
   public long Luid;
   public int Attr;
  }
  internal const int SE_PRIVILEGE_DISABLED = 0x00000000;
  internal const int SE_PRIVILEGE_ENABLED = 0x00000002;
  internal const int TOKEN_QUERY = 0x00000008;
  internal const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
  public static bool AddPrivilege(string privilege)
  {
   try
   {
    bool retVal;
    TokPriv1Luid tp;
    IntPtr hproc = GetCurrentProcess();
    IntPtr htok = IntPtr.Zero;
    retVal = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok);
    tp.Count = 1;
    tp.Luid = 0;
    tp.Attr = SE_PRIVILEGE_ENABLED;
    retVal = LookupPrivilegeValue(null, privilege, ref tp.Luid);
    retVal = AdjustTokenPrivileges(htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero);
    return retVal;
   }
   catch (Exception ex)
   {
    throw ex;
   }
  }
  public static bool RemovePrivilege(string privilege)
  {
   try
   {
    bool retVal;
    TokPriv1Luid tp;
    IntPtr hproc = GetCurrentProcess();
    IntPtr htok = IntPtr.Zero;
    retVal = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok);
    tp.Count = 1;
    tp.Luid = 0;
    tp.Attr = SE_PRIVILEGE_DISABLED;
    retVal = LookupPrivilegeValue(null, privilege, ref tp.Luid);
    retVal = AdjustTokenPrivileges(htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero);
    return retVal;
   }
   catch (Exception ex)
   {
    throw ex;
   }
  }
 }
"@
Add-Type $AdjustTokenPrivileges
[void][TokenManipulator]::AddPrivilege("SeRestorePrivilege") 
[void][TokenManipulator]::AddPrivilege("SeBackupPrivilege") 
[void][TokenManipulator]::AddPrivilege("SeTakeOwnershipPrivilege") 
#endregion

$BuiltinAdmin = New-Object System.Security.Principal.NTAccount("BUILTIN\Administrators")
$BuiltinAdminFullControlAcl = New-Object System.Security.AccessControl.FileSystemAccessRule($BuiltinAdmin,"FullControl","Allow")

#region Create temp folder with Admin owner and full control
$FolderBuiltinAdminOwnerAcl = New-Object System.Security.AccessControl.DirectorySecurity
$FolderBuiltinAdminOwnerAcl.SetOwner($BuiltinAdmin)

Remove-Item $TempFolder -EA Ignore
New-Item -Type Directory -Path $TempFolder

$TempFolderAcl = Get-Acl -Path $TempFolder
$TempFolderAcl.SetAccessRule($BuiltinAdminFullControlAcl)
#endregion

#region Change folder owners to Admin
$Folders = @(Get-ChildItem -Path $Target -Directory -Recurse)

foreach ($Folder in $Folders) {
    $Folder.SetAccessControl($FolderBuiltinAdminOwnerAcl)
    Set-Acl -Path $Folder -AclObject $TempFolderAcl
}
#endregion

#region Create temp file with Admin owner and full control
$FileBuiltinAdminOwnerAcl = New-Object System.Security.AccessControl.FileSecurity
$FileBuiltinAdminOwnerAcl.SetOwner($BuiltinAdmin)

Remove-Item $TempFile -EA Ignore
New-Item -Type File -Path $TempFile

$TempFileAcl = Get-Acl -Path $TempFile
$TempFileAcl.SetAccessRule($BuiltinAdminFullControlAcl)
#endregion

#region Change file owners to Admin
$Files = @(Get-ChildItem -Path $Target -File -Recurse)

foreach ($File in $Files) {
    $File.SetAccessControl($FileBuiltinAdminOwnerAcl)
    Set-Acl -Path $File -AclObject $TempFileAcl
}
#endregion

#region Clean-up
Remove-Item $TempFile, $TempFolder
#endregion

Thank you all again for your help. Hopefully, someone else can benefit from my PowerShell research. The only think left is making it a bit more verbose, but that's for another day. It does what it needs to do, and that in the most harsh conditions where permissions are really messed up.

You can use the SetOwner() method for folders, just like for files.

# Define the owner account/group
$Account = New-Object -TypeName System.Security.Principal.NTAccount -ArgumentList 'BUILTIN\Administrators';

# Get a list of folders and files
$ItemList = Get-ChildItem -Path c:\test -Recurse;

# Iterate over files/folders
foreach ($Item in $ItemList) {
    $Acl = $null; # Reset the $Acl variable to $null
    $Acl = Get-Acl -Path $Item.FullName; # Get the ACL from the item
    $Acl.SetOwner($Account); # Update the in-memory ACL
    Set-Acl -Path $Item.FullName -AclObject $Acl;  # Set the updated ACL on the target item
}