Did you check to see if it was already done? This exact thing happened to me, went too fast past the beginning steps and thought I didn't aurarize the computer. So to check, go to Help in the menu bar. The Authorize Computer selection will probably be greyed out - mine was - so go to the next option, authorization information. It'll probably say it's already authorized. The rep I was on the phone with told me because ADE is a free program, it actually doesn't need authorization. So whether you choose it or not, it's "authorized" as a matter of course. However, lemme know if it's not. Because that'd mean the rep didn't know what she was talking about. (I had gotten pushy trying to fix my ADE so I gave up and called them!) Good luck!
Lovies,
Selenity Jade
Coffee Addict & Insomniac