Try this...
Code:
 
break on

$objWMIService = GetObject("winmgmts:\\.\root\cimv2")
$colPrinters = $objWMIService.ExecQuery("Select * From Win32_Printer Where Default = TRUE")
For Each $objPrinter in $colPrinters
? $objPrinter.Name
? $objPrinter.portname
Next