Set-Acl: Tentativa de executar uma operação não autorizada ao usar a regra Addaudit

Question

Estou tentando executar o script Powershell para definir a Regra de Auditoria na pasta C:\Windows\security na minha caixa do Windows 2008.

Abaixo está o script:

$FileDirList = ("C:\Windows\security")
$AccountName     = New-Object System.Security.Principal.NTAccount("Everyone") 
$FileSystemRight = [System.Security.AccessControl.FileSystemRights]::FullControl
$AuditFlag       = [System.Security.AccessControl.AuditFlags]::Failure
$InheritanceFlag = [System.Security.AccessControl.InheritanceFlags]::None
$PropagationFlag = [System.Security.AccessControl.PropagationFlags]::None

#
#write-OSPBOSbuildLog  "Applying Audit Setting"
#     

foreach ($FileDirName in $FileDirList) {   
#write-OSPBOSbuildLog  ">>>>>  Appying audit setting to $FileDirName"

$AuditRule = New-Object System.Security.AccessControl.FileSystemAuditRule       $AccountName, $FileSystemRight, $InheritanceFlag, $PropagationFlag, $AuditFlag 

$objACL = Get-ACL $FileDirname 

$objACL.AddAuditRule($AuditRule)

Set-ACL $FileDirname $objACL

Mas estou recebendo um erro, conforme mostrado abaixo:

Set-Acl : Attempted to perform an unauthorized operation. 
At C:\IBM\File-Perm.ps1:22 char:12 + Set-ACL <<<< $FileDirname $objACL + CategoryInfo :
PermissionDenied: (C:\Windows:String) [Set-Acl], 
UnauthorizedAccessException + FullyQualifiedErrorId :
 System.UnauthorizedAccessException,Microsoft.PowerShell.Commands.SetAclCommand

Por favor, me ajude a entender quais mudanças eu preciso fazer?