Hi Thunderbird has two levels of password, but the one you are most likely looking for is the one to allow Thunderbird to connect to your email provider and download/send emails. In Thunderbird, use the same password that you use to access your email online (webmail). If you need to change that password, first change it with your webmail account, and then make Thunderbird's setting match. However, if you lost that setting there may be many more that you need to recover, as well as the emails that were saved locally in Thunderbird. To recover those you need to access your old Thunderbird Profile folder, either in a backup, or still on your computer if the Windows reinstall (or repair) kept it - either simply still in Appdata, or in Windows.old. Here's more information about how to find your profile, and get a new install of Thunderbird to connect to your old settings and mail. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data http://kb.mozillazine.org/Moving_your_profile_folder_-_Thunderbird Agnes