Can' t load Vista into Parallels on MBP 17"

I'm new at all the Parallels thing but not at using the Mac I've been a Mac user since 1990 and I need help to install Vista onto my Parallels as I have all the latest software and I had Win/XP loaded into Parallels working great and when I bought my Macbook Pro 17" I was given a letter to send in to receive Vista Business for free I've tried throwing away my Parallels items in my home>Documents>Parallels folder not the folder itself just the contents and when I try to install Vista and get to the point of entering my Product Key it says since you've entered this key you need to 1st install your previous OS and so I reinstalled Win/XP and then tried to Install a New OS and I keep going in a circle

THIS IS WHAT I NEED SIMPLE INSTRUCTIONS ON HOW TO INSTALL WINDOWS VISTA ONTO MY MACBOOK PRO 17" WITH 2GB OF RAM AND A 160GB HARD DRIVE RUNNING MAC OS 10.4.9 and this Mac is about 2mths old so I have the DualCore also. Please help ASAP as I can't stop until I've figured this out and I need your help....​

 

Please do not write in red text. This is a forum of users, not tech-support.

Do you have a full version of vista Business or an upgrade version?

If you have an upgrade version you will have to install XP, then run the Vista installer from within the running XP.

 

Well, it looks like the CD you've received (or, more precisely, the product key) is a Windows Vista upgrade version. It will look for an *installed* Windows XP (or for an XP CD). You can't just install this Vista version by itself: you either upgrade your existing XP Parallels Virtual Machine, or you feed it with the XP CD when asked.