How to Choose a Default Printer in Windows XP
OVERVIEW
The default printer is the first or primary printer chosen when the printer button is pressed or File, Print is chosen in an application.
To change the default printer to a different one, right click on the printer you want as the new default and select Set as Default Printer.
--- OR ---
If you are not comfortable right clicking, click once on the printer to select it, then click on File, Set as Default Printer.