Microsoft Office isn't part of Windows. It's an optional extra that you have to pay for. In order to draw you into paying for it, Microsoft give you a 60 day free trial. After that period, as Mycats states, you'll either have to pay up or find alternative software.
There's absolutely no reason to have Microsoft Office on your laptop. OpenOffice does the same jobs as well, or better, than anything that Microsoft Office can do. It's fully compatible with Microsoft Office so that users can read and edit files produced in Microsoft Office, and vice versa. (Before someone posts to correct me, I'll add that 'fully compatible' is a slight exaggeration, since OpenOffice might not be able to cope with a few Microsoft Office files with incredibly complex macros in them. In practice, the average user never encounters such documents).
So, unless you want to spend money unnecessarily, ditch Microsoft Office and download OpenOffice, totally free of charge, from here:
http://www.openoffice.org/
Chris