To change the permission of a NTFS file: #Add / Change NT Permissions ############################# get current permissions $acl = Get-Acl -Path <FileName>#SID from NT AUTHORITY\SYSTEM $SidString = ‚S-1-5-18‘ # add a new permission $permission = [System.Security.Principal.SecurityIdentifier] $SidString, ‚FullControl‘,’Allow‘ $rule = New-Object -TypeName System.Security.AccessControl.FileSystemAccessRule -ArgumentList $permission $acl.SetAccessRule($rule) # set new permissions $acl | Set-Acl -Path <FileName>    Read More →