When I've clicked on 'Show Passwords' before, they have always appeared - but today this screen was displayed. I thought my user name was: first name (abbreviated), followed by a space and my surname - as it appears on emails I send. As for the password, I never set a master password when I downloaded Thunderbird and imported all my mail accounts. I tried entering the password set for signing into the PC I was using without success. I therefore don't know how to satisfy Windows Security with user name or / and password. If you had this problem and overcame it, please tell me how. Thank you!