Perhaps it created a new profile and set as default so try resetting it. Menu app icon > Help > More Troubleshooting Information Under Application Basics - near the bottom - Profiles - click on 'about:profiles' It opens in a new tab. The current profile will be set as default. You may have more than one profile and it could be the old profile you used. Below it it will say 'Set as default' - click on that button and then click on 'Launch Profile' which will open in a new window. Then close the original Thunderbird window.

I can not get past the set up existing email address. Says unable to log in at server. Probably wrong configuration, username or password. Any ideas?

Why are you trying to set up a mail account?

First you need to see if Thunderbird has the old profile and you just need to tell Thunderbird to use it. Regarding my previous comment....What do you see in 'about:profiles' ? Post an image showing what you see in 'about:profiles'.

If 'about: profiles' only shows one profile............ Did you previously set up your account as an IMAP mail account ? If yes, then email should still be on server. What server are you trying to connect to - eg: gmail, yahoo, BT, etc

You mentioned you had just downloaded Thunderbird, so it is possible your Firewall could be confused and simply not allowing Thunderbird access to the internet, so it cannot access server.

Firewall: Is Thunderbird set up as an allowed program ? What Ant-Virus product are you using as it may also be providing your Firewall? Exit Thunderbird Access Firewall If Thunderbird is already listed as 'Allowed' then remove it, ok it, then go back into Firewall and allow Thunderbird again. If it's not listed as allowed then you need to add Thunderbird as an allowed program.

I was able to find the emails. Not sure if I can load them into TB yet. I was able to see them with firefox browser. That is a big help.

Not sure how to get tb to read them yet. Still working on that. Thanks, Bob