Hello. I have tried multiple times to install Thunderbird 31.2.0 on a computer that is running Windows 8.1 Update 1. After the installation I try to open the program but don't get a Wizard to setup an account. I then manually click on TOOLS-ACCOUNT SETTINGS-ADD MAIL ACCOUNT and nothing happens. If I click on TOOLS-ACCOUNT SETTINGS-ADD OTHER ACCOUNT the only option shown is NEWSGROUP ACCOUNT. I have re-downloaded the file multiple times and checked the file size against a successful installation on another Windows 8.1 computer. I have used Revo Uninstaller to remove the failed installations and also have deleted the Thunderbird folders that remained in APPDATA-LOCAL and APPDATA-ROAMING to complete the uninstall. I have tried reinstalling TB in Safe Mode with the same results. I have gone into Windows Firewall settings and allowed Thunderbird as an exception. I have installed Thunderbird many times on multiple other computers without problems. Additional Information: I am also running Classic Shell 4.1.0. My antivirus is Windows Defender from Microsoft. I have run System File Checker prior to installation. I have checked the computer for malware using multiple programs. I will upload .png screen shots if I can find where that is done in this forum. Any help would be much appreciated.