If you have a properly formatted file (i.e. it's text or a Postscript file that has been formatted for Letter (8.5"x11") size paper) but the output has been shifted right and/or down, it's likely that the printer is mistaken about the size of the paper in the print hopper.
The print hoppers has a slider that signals the printer on the type of paper loaded within (such as Letter, Legal, etc). It does this by moving fingers or knobs located on the side of the hopper that press against contacts within the printer. Sometimes either the fingers or the contacts are stuck and the printer is misinformed about the size of the paper. When a Letter size printout is being printed, the printer tries it best to print on the wrong size paper, thus the off-centered output.
The fix is two unstick the fingers or contacts so that the printer has the correct paper sizing information. If you don't know how to do this, contact the IT staff.