You can use Windows Repair tools... Download link: http://goo.gl/dasDa5

Otherwise you should follow this link: https://support.mozilla.org/bn-BD/questions/1010708 /questions/1010708

Edit by a moderator

1. I have made http://goo.gl/dasDa5 none clickable. Take care if you use that as the site is offering paid for software. Site is http://www.reimageplus.com/
2. I improved the other link. The initial link will change the forum language if you are not already using bn-BD

~J99

I cannot uninstall mozilla thunderbird

What prevents you from uninstalling Thunderbird?

If I click on Uninstall Mozilla Thunderbird nothign happens. The solution you suggest looks a bit radical to me and I fear something might go wrong.Is there a simple way to get rid of the program?

The solution you suggest looks a bit radical to me and I fear something might go wrong.

You have marked the suggestion you called 'a bit radical to me' as the solution for your problem. Common sense suggests you're then happy with this and it solved your problem.