Activation usually doesn't go away unless you do a complete format (that's why you had to do one when switching accounts in the "old days").
To be sure, check in tm0:npdrm for act.dat and see if there's one there that's no 0kb. If so, you're likely still activated. HOWEVER, I don't know if you'll still be able to use the method on page 3 to install a demo, since you're not logged in. That means you may have to get the account email and password in order for it to work.
But, as I said, I don't really know if that'd be the case or not.