What was your original source of Word? Did it come pre-installed on your
computer? What version was it?
Before doing anything else, I would go back into Add/Remove programs, find
Office, and if Word is listed, click to place a check by it. There's an
excellent chance--if it's Word 2003, for example--this this will let you
reinstall Word.
If not, but if Word was preinstalled, then you either received a CD/DVD that
contains the necessary installation files, or there is a folder on your hard
drive that contains them.
Alternatively, you might need to contact the manufacturer of your computer
to find out exactly how to proceed. One option--assuming Word was
pre-installed--would be to do a restore. I don't know about your computer,
but on mine, there is a restoration option that preserves files and
settings, but which puts back programs that were originally installed. If
there is any doubt, contact the computer company.