Can’t remember why I needed to, but if you need to get the SID of an Active Directory user account you can run either of these powershell scripts:
$name = “username”
(New-Object System.Security.Principal.NTAccount($name)).Translate([System.Security.Principal.SecurityIdentifier]).value
or
$objUser = New-Object System.Security.Principal.NTAccount("fabrikam", "kenmyer")
$strSID = $objUser.Translate([System.Security.Principal.SecurityIdentifier])
$strSID.Value