This could be caused by several different factors:

Is there any indentation applied to text?

Is the paper format correctly specified in the Page Setup dialog box?

Also, are you getting any error messages as you print? For example,
sometimes you are getting a message that the margins are outside the
printable area. Although 2 cm seems large enough, it could be worth finding
out the smallest margins allowed (for instructions, see
http://word.mvps.org/faqs/formatting/BottomsDontPrint.htm).

If the problem is with the printer driver, updating it (from the
manufacturer's website) or simply reinstalling it might help.