...How did this happen? (activation code question)

Hi there!

I recently was sent a link by a friend showing me to the Vista RC1 download
site, and was told it was free until a certain date sometime next year. I
downloaded and installed it, finding that by entering nothing in the
activation code field while initially setting up Vista I did not need to
enter a code right away. Over the next few days I had multiple bubbles
telling me to activate Vista. I tried, but both online and phone registration
failed, of which the online registration told me my code was already in use
(I hadn't entered one!)

After much searching I find that I need to be part of MSND and the CPP to
recieve an activation code, but yet I was still able to download it. What can
I do? Are codes useable on more than one PC? Would anybody kindly send me
theirs, if it can be used on multiple PCs?

Thanks in advance, any help is very much appreciated.