I've never known a manufacturer the actually gave you the full version of Office on your new computer unless you buy it. The trial version I got on my laptop didn't let you do any formatting (font, size, alignment wouldn't change). I have a version of office 2000 pro, so I used that, i don't need a million things on office anyway.
I know a few people who have downloaded the entire Office Suite and more from P2P, but that's not the right thing to do, I would stay away from that if you want to be safe. You can get a trial version from the website which is very good, or search Froogle for the best prices.