Hi,
I think this is because Adobe Acrobat Standard is installed in your system.
Just click on the start menu --> and select Printers & Faxes (For Win XP).
You will get a window which shows all the instaled printers in your system.
Find out your Printer in that list, right click on that, and click on
'Set as default Printer' option.
This should sove your problem. If not, pls let me know your operating system
version and printer details...