ADE authorization

I want to authorize my computer that already had ADE installed. The FAQs say that I can do this after the fact by used the "authorize this computer" option in th menu, however it's grayed out! This is really annoying. I want to download a magazine I bought and be able to read it on whatever computer I need to. I want to OWN this purchase, yet there seems to be no way to do it since I originally downloaded ADE without my ID, never realizing that there would be any issue. Can someone from Adobe please help.