After many attempts, I finally found the answer in a CNet forum (post #2). I’ve added how to find the computer and printer name.
On the XP computer.
Get the computer name and printer name.
– Computer Name. Control Panel / System. It’s the “Full computer name.”
– Printer Name. Control Panel / Printers. Right-click the printer. The General tab has the name right at the top.
– These will be entered on the Vista computer in the format “Computer nameprinter name”. Case is significant.
On the Vista computer.
– Control Panel / Printer / Add Printer
– Choose Add a local printer. Click on Create a new Port. The name in the Drop Down box should be local port. Click Next
– Enter the computer name and printer name of the XP printer in the form of computer nameprinter name. It is case-sensitive.