Long ago, a printer would be a device, attached directly to your computer. The earliest computers called a printer a "Line Printer", and let you connect your printer to a physical post on your computer. Some computers might have up to 3 physical ports - labeled "Line Printer 1", "Line Printer 2", or "Line Printer 3", abbreviated as "LPT1", "LPT2", or "LPT3".
Then network printing was made possible. You could setup a printer, locally attached to your computer on LPT1, and share it with your neighbours. You had YourComputer, and you could designate your printer to be shared as YourPrinter1. Similarly, your neighbour might have TheirComputer, and a printer shared as TheirPrinter1. If you wanted a second printer to use occasionally, you could setup your programs to print to LPT2 on your computer. You could redirect your LPT2 to print to "\\TheirComputer\TheirPrinter1".
Then somebody else started writing programs to print directly to "\\TheirComputer\TheirPrinter1", without involving "LPTn".
Now, accessing either a directly attached printer ("LPT1"), a network attached printer redirected (LPT2 redirected to "\\TheirComputer\TheirPrinter1"), or a directly networked printer ("\\TheirComputer\TheirPrinter1") involves specific code in the printer drivers, both in your computer (the client), and in the other computer (the server).
None of these options are magical, and not all printers will have drivers that will support all 3 ways of using the printer. Some drivers will claim to support all 3, but depending upon how your computer, and your neighbours computer is setup, one may work better than another. That's reality.
It appears that not all printer drivers, written for Windows Vista, support the old LPTn standard. If you can't get your network printer to work as "LPTn" redirected to "\\TheirComputer\TheirPrinter1", try bypassing the LPTn redirection.
- Install the Vista printer driver on your Windows Vista computer.
- During installation, you'll be prompted to connect the printer to your computer. Choose the option to proceed with installation without connecting the printer.
- After installation completes, open the Printers wizard from the Windows Vista Control Panel.
- Right click on the entry for the new printer, and choose Properties.
- Go to the Ports tab.
- Click Add Port, select Local Port, then click New Port.
- For the port name, enter the network path and share name of your printer (ie "\\TheirComputer\TheirPrinter1").
- Click OK, and verify that the new port is selected.
- Click OK to close the printer properties.
(Update 10/30): If you're experiencing these, and similar problems with printing, try the Vista Compatibility, Performance, and Reliability Comprehensive Update.