===================================================================== THUNDERBIRD BACKUP - USER GUIDE Version 1.0.0 Computer Info Bits Limited https://computerinfobits.com ===================================================================== WHAT THIS PROGRAM DOES ---------------------- Thunderbird Backup saves a complete copy of your Mozilla Thunderbird mail profile into a single zip file, and can restore that copy later. A profile contains everything that makes Thunderbird yours: * Your email accounts and their settings * All downloaded messages and local folders * Your address books * Message filters and tags * Saved passwords * Calendars, if you use them Because the whole profile is copied, your saved passwords are included in every backup and come back automatically when you restore. You do not need to write them down or re-enter them. REQUIREMENTS ------------ * Windows 10 or Windows 11 (64-bit) * Mozilla Thunderbird installed for the current Windows user * Enough free disk space for the backup (see the Size column in the program for an estimate) The program is a single .exe file. It does not need to be installed. Just save it anywhere you like and double-click it to run. BEFORE YOU START ---------------- Always close Thunderbird before backing up or restoring. Thunderbird locks some of its files while it is running, and files that are locked cannot be copied. The program checks for this and will remind you if Thunderbird is still open. BACKING UP ONE PROFILE ---------------------- Most people have just one profile, usually called "default-release". The profile Thunderbird currently opens is marked "yes" in the Default column and is already selected when the program starts. 1. Close Thunderbird. 2. Open Thunderbird Backup. 3. Click the profile you want in the list (the default one is already selected for you). 4. Click "Back up profile...". 5. Choose where to save the zip file and click Save. 6. Wait for the progress bar to finish. A message will confirm the backup and show its size. The suggested file name includes the profile name and today's date, for example: thunderbird-default-release-2026-07-08-1030.zip BACKING UP ALL PROFILES AT ONCE ------------------------------- Not sure which profile you need? Back them all up. This is the safest choice and takes only one extra click. 1. Close Thunderbird. 2. Open Thunderbird Backup. 3. Click "Back up all...". 4. Choose a folder and click OK. Every profile is saved as its own zip file in that folder, so each one can be restored on its own later. RESTORING A BACKUP ------------------ Restoring never deletes or overwrites your existing mail. The backup is unpacked into a brand new profile folder alongside anything that is already there. 1. Close Thunderbird. 2. Open Thunderbird Backup. 3. Click "Restore backup...". 4. Choose the backup zip file and click Open. 5. When asked "Make this the profile Thunderbird opens by default?", choose: Yes if you want Thunderbird to open the restored profile from now on. This is the usual choice on a new computer or after reinstalling Windows. No if you only want the restored profile available as an extra. Your current profile stays as it is. You can switch between profiles at any time by pressing Windows key + R and running: thunderbird.exe -P 6. Start Thunderbird and check that your mail, accounts and passwords are all there. Restoring works even on a computer where Thunderbird has never been run before. Install Thunderbird first, restore your backup, answer Yes to the default question, and Thunderbird will open your restored profile on its first start. KEEPING YOUR BACKUPS SAFE ------------------------- Your backup zip contains your saved email passwords. Anyone who has the file can read your mail and recover those passwords, so treat every backup like a house key: * Store backups on a drive or cloud folder that only you can use. * Do not email backups or share them through public links. * Delete old backups you no longer need. It is a good habit to keep at least one backup somewhere other than your computer, for example on an external drive, in case the computer itself fails. TIPS AND TROUBLESHOOTING ------------------------ "Some files were locked and skipped" appeared after a backup. Thunderbird (or one of its background processes) was still running. Close it, wait a few seconds, and run the backup again so you get a complete copy. The profile list is empty. Thunderbird has not been run for this Windows user yet, so there is no profile to back up. You can still restore a backup. The Size column shows "..." for a while. Sizes are counted in the background so the program stays quick to open. Large mailboxes can take a few seconds to measure. I restored a backup but Thunderbird opened an empty profile. You probably answered No to the default question. Press Windows key + R, run "thunderbird.exe -P", and pick the restored profile from the list. Can I restore a backup from an older version of Thunderbird? Yes, in most cases. Thunderbird upgrades older profiles when it first opens them. Restoring a profile from a NEWER version of Thunderbird into an older one is not supported by Thunderbird and is best avoided. Where does the program make changes? Backups only read your profile. Restoring writes the new profile folder and updates Thunderbird's profile list (a file called profiles.ini). A safety copy named profiles.ini.bak is saved first, so the previous list can always be recovered. ABOUT ----- Thunderbird Backup is developed by Computer Info Bits Limited. Website: https://computerinfobits.com Copyright 2026 Computer Info Bits Limited. All rights reserved. Mozilla Thunderbird is a trademark of the Mozilla Foundation. This program is an independent tool and is not affiliated with or endorsed by the Mozilla Foundation.