I installed my third license on my new MB Thursday night. Did the two updates. THen Friday, while my college daughter was home for the weekend, I discovered that I must have used the key we used for her activation in August. (Of course, can I remember which one that was? Of course not.) So now I have to uninstall and reinstall. Machine is new, so it's not a big deal. Just kind of aggravating, particularly as I may make the same mistake over again.