Hello there Qatar Munir. We have read your message. We try to help you. Your Thunderbird software is not starting. Try to shut down Thunderbird. Delete the program folder on your pc. C:\Program Files (x86)\Mozilla Get a fresh reinstall from https://www.thunderbird.net/en-US/thunderbird/releases/ You will not lose your data keep your login name and password. But for the safety of your data try to make a backup from your pc or files. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile Send me a message after trying. Greetings Firefox volunteer.