you can Follow these easy steps to add a shared printer to your Vista PC.
1. Assure that you have the correct print drivers on your Vista PC for the printer you want to use.
2. On the XP Computer, setup the computer and printer to be shared.
3. Using your Vista computer, go to the Control Panel. Choose “Printer”. Then choose “Add Printer”.
4. Choose “Add a local printer”. Go to the Port Tab.
5. Click "Add Port", then select "Local Port", then click "New Port."
6. For the Port Name, enter the exact network path and shared name of your printer.
Example: \\HOMEPC\Printer2 - use the exact case that’s on the shared XP computer. So if the name of the computer is PClocal and the name of the shared printer is HPxx123, the path should be: \\PClocal\HPxx123
7. Click "OK" and make sure that this new port is selected with a check in the checkbox.
8. Click "Apply" and then "OK", to close the printer properties.
9. You should now be able to print from your Windows Vista PC to a shared printer located on a Windows XP PC. Try printing a test page to be sure it works.