Hi Deepdiver!
As long as you registered your PE with the same Adobe i.d. and password you used on your PC you should be able to transfer books through Adobe Digital Editions. One thing though -- I do not know how Nook works. I understand Barnes & Noble has their own system requiring you to use a credit card as a password or something like that. I don't know at what stage that happens, do you?
Hope you figure it out!