I'm not quite sure what you're describing. Can you show us a screen shot? Use Snipping Tool to get a screen shot.
You could always nuke your Thunderbird profile and start from scratch.
THIS WILL DELETE ALL YOUR EMAIL AND ACCOUNT SETTINGS
You can nuke your profile by deleting the Thunderbird folder under AppData.
AppData is a hidden folder under your user account that stores information for programs. Firefox has it's own folder, as does Thunderbird, and many other programs.
To get your app data folder simple click start and type %appdata% into the start menu search bar then press enter.
After deleting the Thunderbird folder, TB will think it's freshly installed and prompt you to setup your email accounts.