If you want MS Office, then you need to purchase them from Microsoft.
Office is not a part of Vista, we have to install it separately.
For your information, 60days trail version MS Offiice will be available from Microsoft.
After 60 days again you have yo purchase full version MS Office.
If you don't want to buy, after every 60 days, you can try reinstall after another 60days.
Let me explain the procedure to download the trailversion MS Office:
Download and install the MS Office 2007 from the below link:
After installing the Trail version MS Office from the above link, then you have to contact Microsoft to get the trail version MS Office key for 60 days.
You can request for trail key from the below URL:
Hope this will help you.
Please reply if you need further assistance on this.