You will have to go to Docs and Settings, your user name, open Application Data folder, scroll down to Thunderbird and delete the folder. That is where your settings are stored and they are not removed when you uninstall Thunderbird.
Been using thunderbird mail. Updated to newer version and just stopped. All done was load up on something. Didn't get new messages, etc.Had to go to task manger to get out. I went to add remove programs and uninstalled. Put the older version in but everything still there.Wouldn't let me start from scratch. Can't uninstall thunderbird mail on my xp computer. Any suggestions?