Here is a script I got earlier on today. You need to copy it into notepad and save as VBS then put it as a logof script
' RemovePrinterConnection.vbs - Windows logon script
' VBScript to - Network Printer
' Author Guy Thomas
' Version 1.4 - April 24th 2005
' ------------------------------------------------------'
Option Explicit
Dim objNetwork, strUNCPrinter
strUNCPrinter = "\\JANUS\ICT LAB 5500N"
Set objNetwork = CreateObject("WScript.Network")
' Section which removes the network printer
objNetwork.RemovePrinterConnection strUNCPrinter
'WScript.Echo "Check Printers folder NO: " & strUNCPrinter
Wscript.Quit
' Guy's Logon Script ends here