I'll code an easier way to send referral links next week, but for the time being if you click on the thread tools button (top right of each thread) and click "e-mail this page" you will see it creates a link with a referral ID in it. If a user visits a site through that link it counts as a referral
So, you can send this thread link to a friend using that tool - but add an explanation. Once they have registered it should count as a referral (or they can enter your name on the registration form, I think!).
Most everyone I know is stuborn and stuck on XP - They wont even try vista and chances are they would think Win7 is even worse until it comes out anyway. Those that are on vista says they will wait till Windows 7 comes out.
Once it comes out and the price is not outrageous. I'll think about sending a few referrals then!! Even though its a RC version its still in testing stage!!