It sounds that in the print options you may have the Comments option selected
and/or Track Changes with the balloons options selected to print as well.
Deselect these options as well as turn off Track Changes balloon in your
document.
Hope this helps
DeanH

All printers have a certain nonprintable area on all sides of the page.
Usually this is largest on the trailing edge (bottom of portrait pages, one
side or the other of landscape pages). This is usually larger for inkjet
printers than for lasers. I suspect that is the problem you are running into
(see http://word.mvps.org/FAQs/Formatting/BottomsDontPrint.htm). There's
really not much you can do about this. For general help with setting up
columns, see http://word.mvps.org/FAQs/Formatting/UsingColumns.htm.

If in fact the problem is that Word is allowing space for the "balloons" of
comments or tracked changes (which others have suggested but I rather doubt
is the issue here), the settings wrt the balloons themselves are found on
the Track Changes tab of Tools | Options. To remove the changes, on the
Reviewing toolbar, click beside Accept Change and choose Accept All Changes
in Document; then click beside Reject Change/Delete Comment and Delete All
Comments in Document. Make sure that Track Changes is turned off (if TRK is
black on the status bar, double-click to turn it off).

If you want to continue to track changes but print without the markup,
switch to Final view before printing or, in the Print dialog, select
"Document" rather than "Document with markup" in the "Print what" box.