Try with New Thunderbird profile

• https://support.mozilla.org/en-US/kb/using-multiple-profiles
• http://kb.mozillazine.org/Profile_folder_-_Thunderbird

Backup your profile date and restore it

• http://www-archive.mozilla.org/support/thunderbird/profile#backup

Start *Windows* in safe mode with networking enabled.

- Win8 http://windows.microsoft.com/en-US/windows-8/windows-startup-settings-including-safe-mode

- Win7 http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode

- XP http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx

Still in Windows safe mode, start Thunderbird in safe mode

- https://support.mozilla.org/en-US/kb/safe-mode

Does the problem go away?
What is your anti-virus s/w?

Nope sorry, still freezes in Windows (and Thunderbird) safe mode.

Antivirus program is ESET-Smart Security 7 but I tried to turn off as much as I could in it to see if it was to blame and it froze all the same.

I'll try this if I can, but manuals are old and seem to have little to do with Windows 8...

Hello,

Certain Thunderbird problems can be solved by peforming a Clean Reinstall. This means you remove Thunderbird's Program Files then reinstall Thunderbird. Please follow these steps:

1. Download the latest version of Thunderbird from http://www.mozilla.org/en-US/thunderbird/ and save the setup file to your computer.
2. After the download is complete, close all Thunderbird windows (Click Exit/Quit from the menu button on the right).
   • Windows:
     • C:\Program Files\Mozilla Thunderbird\
     • C:\Program Files (x86)\Mozilla Thunderbird\
   • Mac: Delete Thunderbird from the Applications folder.
   • Linux: If you installed Thunderbird with the distro-based package manager, you should use the same way to uninstall it - see Install Thunderbird on Linux. If you downloaded and installed the binary package from the Thunderbird Download Page, simply remove the folder thunderbird in your home directory.
3. Now, go ahead and reinstall Thunderbird:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to open Thunderbird after clicking the Finish button.

WARNING: Do not run Thunderbird's uninstaller or use a third party remover as part of this process, because that could permanently delete your Thunderbird data, including but not limited to, extensions,emails, personal settings and saved passwords. These cannot be recovered unless they have been backed up to an external device!

Please report back to see if this helped you!

Thank you.

A reinstall solved it. Thanks.