Set up Adobe Editions without authorisation how do I change

I bought a new laptop and tried to set up Adobe Digital Editions to download my E-books.  When I tried to enter my Adobe username and password it said it was linked to another computer and couldn't be used, so I proceeded with authorising the computer.  Now I can't move any of my ebooks to my ereader as they can only be read on my computer.  I have set up a new Adobe username and password and have tried to authorise the computer but I get the message 'Activation Server Error - code E_AUTH_NOT_READY'.    Digital Editions encountered an error in the activation server.

Any ideas what I am doing wrong and how to rectify this?

Thanks

Julie