Artigo de suporte da Microsoft KB 931719 .
Outra referência
Please try on your VISTA machine:
Control Panel -> Printers -> Add a printer -> Add a local printer ->
Create a new port: Local Port ->
Enter a port name: \Your_XP_machine\Shared_Printer [REPLACE W/ YOUR INFO]
Pick appropriate driver from list provided by Vista [Lexmark 4800]