You can download a free trial version of Office 2003 (which includes
Word 2003) from
http://www.microsoft.com/office/editions/prodinfo/standardtrial.mspx.
The trial version is the same as the full version, except that it only
works for a limited time. When the trial period expires, you will have
to convert to a perpetual license (in other words, pay for it) if you
want to keep using it. If free is important, you might consider Open
Office (see
www.openoffice.org), which can open Word files and "save as"
in Word format, and it's free forever.