I am using a new Dell computer with Windows 7. I am trying to print PDF files with a Xerox 7750 printer. I have downloaded the Xerox driver to the new computer, the printer is connected via USB. Each time I try to print the PDF file(s), they do not print on the entire page (8.5x11). All data on a page is printed but it is printed as a 1/2 page and in landscape, not portrait. I have tried to adjust the printer settings via Windows 7 (print window) but cannot get the document printed correctly. How do I fix this problem?