yeah, the windows bit threw the whole thing off. I used to work for BCI.. A company that when installing huge networks, installs the same copy of windows 986865 times. Then they provide individual, unopened copies of windows to the clients. This gives them license to have a copy on each of the systems, but the same copy of windows, along with the security key, matches over the entire network. Gates never shit himself over that.
And no, it wasnt some master key.. The simply opened one copy and used that key for every computer.