Dim $arrDefaultPrinter, $strDefaultPrinter
$arrDefaultPrinter = ReadValue('HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows','Device')
If Instr($arrDefaultPrinter,",")
  $strDefaultPrinter = Split($arrDefaultPrinter,",")[0]
Else
  $strDefaultPrinter = $arrDefaultPrinter
EndIf

Dim $WSHNetwork, $objPrinters, $i, $strNewPrinter
$WSHNetwork = CreateObject("WScript.Network")
$objPrinters = $WSHNetwork.EnumPrinterConnections
For $i=0 To $objPrinters.Count -1
  If Instr($objPrinters.Item($i), "\\oldserver")
    $strNewPrinter = Join(Split($objPrinters.Item($i),"\\oldserver"),"\\newserver")
    $=DelPrinterConnection($objPrinters.Item($i))
    $=AddPrinterConnection($strnewPrinter)
    If $objPrinters.Item($i) = $strDefaultPrinter
      $=SetDefaultPrinter($strNewPrinter)
    EndIf
  EndIf
Next