That is a setting in your printer driver, not directly in Word. Go to Start
> Settings > Printers & Faxes, right-click your printer, and select Printing
Preferences. Look for the check box in there. If you don't see it,
right-click the printer again and select Properties. Different printer
drivers put it in different places.
--
Regards,
Jay Freedman
Microsoft Word MVP FAQ: http://word.mvps.org