When trying to download previously purchased books to new Sony Reader with new Adobe ID, get error message: "Download failed. Content has already been licensed to another user." Also, existing books in Reader library get error message: "This computer is not authorized to preview this eBook." How can I get these books to be downloadable/viewable on new Adobe ID?
The error message is correct. The books are licensed to the old AdobeID, and not your new AdobeID.
Your choices are:
1.) Contact the book seller to ask for a redownload - they may or may not do this for you.
2.) Create a new OS User account, and authorize ADE on that account with the old AdobeID