If you already have the machine in question authorized to your AdodbeID, then at minimal level you just need to back up your books (the .pdf and .epub files). However if you want to keep you book and any folders you have created, it would probably be best backup your entire "My Digital Editions" directory.
When moving to new machine (and doing a resintall/upgrade of the OS counts as a new machine), you will need to authorize, and then copy over your books (or your DE directory), and you'll be up and running.
Thanks for the kind response Jim. I'll back up the hole directory as that will catch all the files.
Yes, Me too,
Right now since restoring my XP machine I can't get my purchased books and load it into my Palm Centro,also have been hard rest. It's a horror if you need to restore your library. I'm trying to use Adobe Reader for Palm OS to install my books back into my Centro. Any Help? Abobe Digital Edition books have or I can't find any help in resolving this issue. I have the PDFs on my hard drive.
Any linds to the answer?
The answer is that you cant. There is no supported software for reading encrypted eBooks (compatible with Adobe Digital Editions) on your Palm.