I love thunderbird but it stopped working..I have uninstalled and reinstalled the application and the problem is still there. I cant open links in the email. When I try to open the email I get a message that reads CHOOSE APPLICATION.. Why?? How can I fix this?? What is the application file I am looking for?? Please help, I miss using Thunderbird email.. I am 64 and need an step by step instructions to fix this..