Using Cubase LE5

Hi. I bought a Lexicon Alpha and am trying to use it. I installed the Cubase LE5 it came with, both disks, but every time I try to open the software it tells me I need to register. It directs me to this site, I created an account and it keeps asking me for an activation code. There was no code in the box. How do I get one? Why is this so hard to do? All I want to do is use the device and I have to jump through all these hoops.