@Interface However you worry will not solve the problem, if there is any. Try getting your CD back. Be subtle trying to convince your friend that you WILL ADD so new features to the CD that it WILL BE a STORY. Otherwise, let a problem happen. There are lawyers. I'm not sure if it's efficient to email Microsft so that they can ban your CD-Key and give you another one. This way, your friend can't activate his (actually your) copy.