I would also recommend placing a variable in front of the AddPrinterConnection and SetDefaultPrinter functions. This will catch the return codes of the functions preventing them from displaying 1's and 0's in a console.

 Code:
$ID = left ("%ClientName%", 15)
$PrinterList = Split(ReadProfileString('%logonserver%\NETLOGON\PRINTER\Drucker-ThinClient.ini', $ID, 'Drucker'), ';')
$DefPrinter = ReadProfileString('%logonserver%\NETLOGON\PRINTER\ThinClient.ini', $ID, 'Standard')
For Each $Printer in $PrinterList
  $rc = AddPrinterConnection($Printer)
Next
$rc = SetDefaultPrinter($DefPrinter)