Found this posting very helpful for the PacketPrivacy.
In this example I am specifically looking for computers running Windows 7.
$w = [wmi]''
$w.PSBase.Scope.Options.Authentication = 'PacketPrivacy'
$w.PSBase.Scope.Options.Authentication
Get-QADComputer -OSName 'Windows 7*' | Select-Object Name | `
Foreach {
Get-WmiObject -ErrorAction SilentlyContinue `
-Namespace 'root\cimv2\Security\MicrosoftVolumeEncryption' `
-Impersonation 'impersonate' `
-Authentication $w.PSBase.Scope.Options.Authentication `
-Class win32_EncryptableVolume `
-ComputerName $_.Name | Select __Server, DriveLetter
}
Enjoy!