Speaking of that, I have had a experience similiar to that where I have used a restore disk, and it never asked to be activated.

Even if you can't activate, you can always call M$ tell them you had to reformat, and its not letting you activate it. Kinda silly how they have all these acivation keys to keep you from pirating their software, and all you have to do is call them up and they pirate it for you.