32 or 64 bit is no real issue, so you don't have to worry about that.

Before we're discussing what to do, a little background on TB.
TB has its mail directory, in that mail directory you'll find two types of subdirectories, the first type is the account directory, the second type is the directory matching with a common folder.
TB identifies its accounts with the name of the account directory. It's a bit silly, but you can have two identical accounts with different account names, it's not unlikely that your ISP will generate error messages when try to access them simultaneously, but there shouldn't be any other problems with that.

The easiest way to merge everything would be to copy the account directories from your old disk to your new system, but take heed that things wiull be overwritten when the names of the account directories are the same. Them being the same isn't unlikely as you'll have them configured identical.
If you've got the same names, then rename the new account, you can do that in TB:
Sel ect account -> Account -> Properties -> General -> Name: change the name -> OK
And set the properties of the new accounts to not to collect mal automatically (just in case)
Account -> Properties -> Options -> Uncheck 'check mailbox at start-up' and 'periodical checking'
So now you've got the names of the accounts different.
Close TB
Now copy the old account directories to the current mail directory
Now there's the issue of your address book, you've used your accounts only for emergency purposes, so I guess that your new address book doesn't contain any addresses and you can overwrite it: Copy the file thebat.abd from old to new disk
Now start TB
Add your restored accounts via:
Account -> New -> account name - TB will recognize the presence of the old account and will accept those settings and message base.
Do this for every old account
Now copy/move the messages fr om the new accounts to the old accounts and delete the new accounts

In case you had common folders (folders not belonging to a single accoun) in your old setup, copy them the same way you did the account directories and press Ctrl-Alt-Shift-L with the account tree pane selected.

I hope this is clear, this will only work in two situations: 1) Both accounts are unencrypted or 2) both setups have the same amster paasword.

Hi, is this still the only way to merge two installs of The Bat? Just wanted to check as I am today in a similar situation. I had TB running on an old laptop (A). Got a new laptop (B), installed TB and copied all data from the old laptop. Did not delete anything from the old laptop. I used TB on the new laptop for a few weeks, then the new laptop died and was sent for repairs. During that time, I used TB on the old laptop. Today I have both laptops operational.

Laptop A has messages that laptop B does not have.
Laptop B has messages that laptop A does not have.

I need to end up with laptop B (new) having all messages from both laptops.

Any help would be appreciated.

Andy

Rick, thank you. I tried the method you described but am unable to see folder1 in TB, after pressing
CONTROL ALT SHIFT L, I get the msg ~ "0 folders found" or similar. I've verified I am using the right path.
Am about to try the Mail Synchronization method but am a bit worried as there is only high-level description of it in the Help file.
....
... after some time... the Synchronization process appears to be doing something, I am seeing the progress bars on both laptops moving slowly, at different paces.. crossing fingers
.. have discovered that the shared sync folder must have a '\' at the end of the path otherwise the process won't budge..