I assume you are talking about Microsoft OFFICE 2003?
That is not available legally as a free download.
However, there is a free alternative called OpenOffice.org which is totally free and legal.
It will read in documents in MS Office format and also allows you to save them in MS Office format. I use it all the time as substitutes for Word, Excel and Powerpoint and they are all quite happily read in by others using MS Office.