Here are the steps. This will bring a full copy of accounts and folders and settings to the new pc. The versions of thunderbird should be the same or nearly so. That is, if thunderbird on old PC is years behind on updates, I suggest updating there prior to copying to a pc with the latest release.

Here is the link for moving a profile in Windows when installed in default location:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

here is the info in brief steps:

1. ensure thunderbird is NOT running on old machine
2. enter %appdata% in search window on task bar and press Enter key
3. this should open windows file explorer in Appdata\roaming folder
4. highlight the Thunderbird folder and copy to external media
5. ensure thunderbird is installed on second computer and NOT running
6. enter %appdata% in search window on task bar and press Enter key
7. you should be in Appdata\roaming folder , copy&paste the exported Thunderbird folder there. This may prompt to overwrite an existing folder of same name. allow it
8. start thunderbird and all should be there

OK will give it a try!! Thank you...will let you know. Question..I installed TB on new W11 but did NOT enter any email as requested right?

Yes, the profile copy will bring everything over.

Your instructions were great! The only issue I had was on the W11 when I put in the %appdata% is brought me to an internet search so I did a RUN and typed it there..all emails are there!!! Took a bit to update but they are there..getting used to this W11 is awful..menus are different and small etc. but I guess I will have to get used to that. Thank you again for your help.

Question to verify that these LOCAL folders are independent of each laptop and only the IMAP emails will be updated on either?

True, The local folders are independent. I'm glad all worked out for you. W11 is good, but takes some adjustment. :) Thanks for the feedback. :)