If you want to use Windows Vista and you want to be able to print to a network printer, you’re going to have to use UAC. You turned it off? Turn it back on. You’re using the in-built “Administrator” account? Log-out and log-in as a normal admin. Microsoft says you have to use UAC to get a printer installed. If you don’t, you get this ugly message:
“Windows cannot connect to the printer. The specified print monitor is unknown.”
Exactly why this message shows up isn’t clear, it has nothing to do with the printer you choose to use or the process you take. This particular message is displayed when trying to add a printer via the wizard: