For backup? I'd go to the Address Book, select an address book (e.g Personal Address Book) and in the menu, open Tools|Export and save it as an LDIF file. You'll need to save each internal address book (e.g. Personal Address Book, Collected Addresses etc) in its own separate file.

However if you want to use your address books somewhere else I'd choose CSV format.

But if you're worried about backup, why not backup your whole profile, and protect your stored messages and your account settings too?

https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data?redirectlocale=en-US&redirectslug=profiles-tb

Zenos I thank you for responding, providing initial how to info. Unfortunately I don't get very far along in the steps. My CD is in the PC with it's door closed. I go to Address Book, but don't see option of two address books ie Personal and Collected. When open Menu, open Tools, click on Export , enter title Addr Book, and save as LDIF , nothing more seems to happen; no blinking light , and nothing is added to the CD.

Sorry to trouble you, but wonder if you might have a clue as to what next I should do.

Do you copy things to CD often? Is this a process you're familiar and comfortable with?

I don't use Windows a lot so any advice I give here may be out of date or just plain inaccurate.

Writing to a CD requires specialized software. It's not just like writing to your ordinary hard disk. Windows helps you (or, as an alternative view, hides the details) when you insert a blank or writeable CD by offering a window where you can collate files you want to write to CD. When you have lined up all your ducks you tell it to go ahead.

I see your task as three steps:

1. Create the files
2. Marshall them into an appropriate place
3. Write them to the CD

The CD-writing support built into Windows will help you with the last two steps, by offering the preparatory window for your files, and then doing the writing to CD.

Note that with CDs it works better to do all the writing at once, not file by file. Whilst you can do file by file (it is called "multi-session") my experience is that multi-session CDs are more likely not to work well in other computers or devices. But then I haven't used a CD for backup for some time and I may be hopelessly out of date.

So, to look at step 1. Write your LDIF files to a folder on your hard disk. Then put those files where the CD writer can work with them - that's step 2.

You need to "expand" All Address Books to see the component inner address books. Try double-clicking it. Or click on the tiny arrow or + sign next to it.

Zenos, it is good of you to be so very helpful. I didn't realize what all would be involved with such a project. I'm not going to pursue it any further.

I truly do thank you for all the trouble you went through . My compliments to YOU !

Tom.