To read your old books you need to use your old ID.
If you still remember the password for it, it doesn't matter too much that it uses an old email.
You can deauthorize your computer, and reauthorize it with your old id.
Also deauthorize any devices you have authorized with your new id (ctrl-shift-E to ADE with device plugged in), and reauthorize.
If you want to change the emails around so that the old ID is associated with your new email, you can change the emails for the ids. If you are going to do this, do it before reauthoizing your computer.
- You must first log on to your new ID on the web and change its email to something different (probably doesn't even have to be a real email, not sure). Now forget about that new ID for ever.
- You then log off and log into your old ID on the web and change its email to your new email.
- Now you should be able to register computers and devices with you old ID but new email.
To change email associated with an id see http://helpx.adobe.com/digital-publishing-suite/kb/changing-id-email.html
- Navigate to http://www.adobe.com.
- Click the Sign-in link at the upper-right corner of the screen.
- Sign in with the existing email address and password.
- Click the user name in the upper-right corner and choose My Information.
- Change the email address (and password if you like) and click
the Save my Changes button.
If you have forgotten the password to the old ID and the email is now defunct, you will have to contact Adobe support (live chat at http://www.adobe.com/support/chat/ivrchat.html may be able to help)
F1 should give help on ADE.
It's pretty bad software, designed by someone without knowledge of the first principles of UI design (such as discoverability).
Thank you - that worked perfectly and best of all I didn't lose the books that I already had. That was my biggest worry. Otherwise I could have just started out clean.