First, Thunderbird is not an email account. It is a program that allows you to access your email account(s) from one or more email providers, like your ISP or gmail, etc. Second. The password used to access your mail account is assigned by your ISP or email provider, not by Thunderbird. Thunderbird will 'remember' this password for you, and will use it to automatically access your mail accounts and show your mail within the Thunderbird program. To access your mail on a different computer, you will need to use the password that is assigned to you by your ISP. If you cannot recall the password, and your thunderbird profile (where the passwords are 'remembered') is lost, or not available, you will have to contact your mail provider and follow their procedures for getting your password reset. Most ISP's provide web access to your email and have a log-in screen where you enter your username and password to continue on. Look on that log-in screen for a link for 'Forgotten Password'. A password may be sent to an alternate email address that you have registered with your ISP, or you may be allowed to change/enter a new password after answering some security questions. TB-38.3 Win10-PC