Hi The most straightforward way is to take a backup of your profile folder, an approach that works for both Firefox and Thunderbird. This is then something you can use with a clean install of Firefox or Thunderbird to restore settings and messages. For Firefox, the instructions to back up your profile folder are [https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles#w_backing-up-your-profile here]. For Thunderbird, the instructions to back up your profile folder are [https://support.mozilla.org/en-US/kb/profiles-tb#w_backing-up-a-profile here]. I hope this helps, but if not please come back here and we can look into a different solution for you.