First thing to do is a little prep work with the OE Address Book so it can be restored to it's current state.
All of the following should be done with OE closed.
Create a shortcut to the Address Book folder and place it on your desktop. This will make it simpler to get into it as you'll need to access it quite a bit.
Open the folder at
"C:\Documents and Settings\username\Application Data\Microsoft" (username being the name you log in with) and right click on the
Address Book folder.
On the menu, click Send To>Desktop(create shortcut).
Go to your desktop and click the shortcut to be sure it opens the Address Book folder. You should see 2 files, one named
username.wab and one
username.wab~.
If there is also a text file or a .old file, you can ignore them. You only need to be concerned with the WAB's.
Copy both of these files to your desktop.
Also make a second copy of both and put them in your My Documents folder (or any place where they will be safe) and then don't touch them again until you're done. This second copy is very important to do.
You'll be working with the WAB files on the desktop and the second copy is a redundant backup in case you mess up.
If you want an even more redundant layer of safety, you can Export the Address Book to a WAB file or CSV file that can be Imported back to OE.You'd lose your folder structure on the Import from it, but it would guarantee the recovery of the contacts.
In the
Address Book folder, click the username.wab and your Address Book should open and show all AB's for all Identities in the left side folder tree with their respective subfolders.
Thunderbird doesn't use subfolders in the Address Book. Each subfolder in OE will be Imported as a separate AB.
Since T-bird Imports the entire contents of the WAB file into a single AB, you need to delete everything you
DON'T want.
Start with Importing the Main folder. Delete all subfolders leaving just the Main and close the Address Book.
Open TB>Address Book. Click Tools>Import.
Place a check by Address Books>Next.
Select Outlook Express>Next.
If the Import is successful, you'll have an AB named Outlook Express Address Book.
You may have to click a different AB and then go back for the contacts to load the first time.
If they are there and look OK, right click it and click Properties. Change the name to Main (or whatever it was in OE).
You can leave the TB Address Book open as you'll be doing more Importing.
Now for the trick to this.
In the
Address Book folder,
delete the WAB file you modified.
Go to the
desktop and right click the
username.wab.
Click
COPY on the menu.
Right click inside the Address Book folder and click
Paste on the menu (or click Edit>Paste on the menu bar).
Open the username.wab and it should be back where you started showing all folders and subfolders.
To Import subfolders as AB's in T-bird, you first need to empty the Main of it's contacts (you can't simply delete the Main without also deleting it's subfolders).
Select the Main in the left pane, click a contact in the list on the right pane.
Click Edit>Select all then File>Delete. The Main should now be empty of contacts.
(Note: If you don't want to have to do this again for each subfolder you want to Import, rename the WAB on the desktop to username.old and then make a COPY of the WAB with the empty main and place that on the desktop to use instead.)
Now delete all subfolders except the one you want to Import and close the WAB.
Run the TB Import again and you should get an Outlook Express Address Book that contains only what was in the subfolder you left in the WAB.
Rename it to the same as the subfolder.
Back to the Address Book folder and delete the WAB.
Copy the WAB from the desktop into the folder and repeat the steps to leave only the next subfolder.
Just keep doing that until each subfolder of contacts in the OE WAB has been Imported into a separate AB in T-bird.
Take your time and be methodical. Check each Imported AB to be sure it's what you want as you go along. If you mess up and Import the wrong thing (forgot to empty the Main or picked the same subfolder to leave), just delete the Imported AB in T-bird and redo it.
Assuming you've read all this and your eyes haven't glazed over

, and you still want to give it a try, I would suggest you do a "Dry run" first (go to the different places and see if the instructions match what you see).
Hopefully I haven't left out anything (what's obvious to me may not be obvious to you because I've done it before).
If you need further explanation of any part, or any questions, please ask and I'll try to make it clearer.