The two default address books, Personal Address Book and Collected Addresses, can be transferred directly by copying abook.mab and history.mab from the old profile to the new one. Other address books in .mab format, e.g. impab.mab, impab-1.mab, can be imported if the MoreFunctionsForAddressBook add-on is installed.

https://support.mozilla.org/en-US/kb/installing-addon-thunderbird

Hi Bruce, Your address books are contained in files with MAB extensions in your profile folder.

• abook.mab is your personal address book.
• history.mab is your collected address book.
• Any other address books you have created will be named accordingly, with the *.mab extension added on.

1. Open the Thunderbird address book window, so Thunderbird creates it's own abook.mab file.
2. Close Thunderbird and replace the newly created abook.mab with your saved one.

To restore additional address books, create new address books in Thunderbird, then rename the old MAB file, so that it will replace the newly created one.

I am not really good with computers, can you give me a step by step menu of how I do this. Like I said, I have found the profiles folder on the old computer hard drive which I can copy to a thumb drive, should I only copy the abook.mab & history.mab from that file? Do I rename it so that it does not overwrite the new address book? How do I copy the one and add it to the address book, do I paste it?

If all your contacts on the old computer are in Personal Address Book and Collected Addresses, then copy abook.mab and history.mab to the thumb drive. Any other address books you had will be stored in other .mab files.

If you already have entries in Personal Address Book and Collected Addresses on the new computer that you wish to keep, create a new address book in Address Book from File/New/Address Book, name it e.g. PABbak, then select the contacts in Personal Address Book and add them to PABbak by drag and drop. Do the same with Collected Addresses if you want to retain the current entries. Then, close TB and copy abook.mab and history.mab from the thumb drive to the new profile folder, overwriting the existing files. When you open TB Address Book, the contacts from PABbak can be added to Personal Address Book if necessary by drag and drop.