1. This <a href=”http://www.geekzone.co.nz/forums.asp?ForumId=45&TopicId=12525″>forum page</a> tell you who to call to get XP.
The basic jist of it is that you have to find a Windows XP CD from somewhere, then install. When you get to the activation screen you have to call Microsoft to get a key. You’ll need to give them your Windows Vista key so that they can mark it as being used to downgrade.
2. Yes that’s possible. You shouldn’t need the Vista service pack.