Please see here for a freely downloadable MSI package of Thunderbird 18.104.22.168:
Features of this package include:
- Free of all Windows Installer ICE Validation Errors.
- Fully supported under many corporate Microsoft Windows based software package deployment solutions including Microsoft Active Directory, Microsoft SMS, Novell ZENworks and Altiris.
- Allows deployment to non-Administrative users providing usability on typical "managed" (locked-down) environments.
- Allows unattended installation. No user intervention is required.
- Full upgrade support for previous Thunderbird MSI packages (no need to uninstall old versions first)