I just installed this on my setup (XP, ProTools 8) and everything worked without a hitch. The response code came in a couple of minutes and I had no trouble whatsoever authorizing it.
As far as I can gather, you need to authorize it as you only get a 14 day demo if you dont.
I installed it grand in Cubase on the Mac, and got the code in about a minute. When I installed it, it gave a summary at the end and it said, "Trial activation started" then "Autorized.." so I assume if I didn't authorize it, it would stop after the 14 days.