Installed NIS2012 and have a question

So I first uninstalled NIS2011 and after that used ccleaner and restarted my PC, even though it wasn't necessary, then installed NIS2012, and here is my question; NIS2012 detected somehow I have a working license for the program and inserted it automaticly, no problem with that, I think it's cool but how the hell does NIS2012 pick up the key, I had uninstalled NIS2011 and removed everything even my settings and so ?

 

Anyway, NIS2012 looks and feels great.. congrats SYMANTEC.. YOU'RE A TRUE WINNER!!!