Migrating Mozilla Thunderbird From One Computer To Another

Thunderbird 3Mozilla Thunderbird may be an excellent email client (and PIM with the right extensions) but for all the wealth of extensions available and it’s myriad of import options, it’s still incredibly difficult to export data such as email, accounts and settings.

I faced that very problem today.

When I’m developing or doing video editing on my main laptop I don’t want to have my email client running. Having it open is not only a distraction but sucks up valuable resources, so today I decided to install a second copy of Thunderbird on my other machine so I could access my email no matter what I was doing or running.

I access all of my email through IMAP, so if I had just a single email address I wouldn’t have worried too much about just installing Thunderbird and manually setting up the account. Unfortunately I am not blessed enough to get by with just a single email address, not even remotely close, so other methods were required.

The method I’m about to show you will work on Windows XP, Vista, Windows 7 & Windows 8, can be accomplished in less than 10 minutes and will allow you keep all of your email settings and email (doesn’t matter if you use POP3 or IMAP).

In order to make the migration, you’ll need a flash drive (preferably with a large storage capacity if you are a POP3 user), portable hard drive or a network connection with shared folders between both machines.

I’ll be explaining how to do it using a flash drive or portable hard drive.

Okay lets get started shall we?

Download the latest version of Thunderbird to the machine you want to install it on ans start the installation process.

While that is installing got to the machine where your email currently exists.

Make sure that Thunderbird isn’t running and plug in your thumbdrive.

Windows Vista and Windows 7 navigate to the following location:


Windows XP users browse to:

C:\Documents and Settings\Paul\Application Data\Thunderbird\Profiles

Inside that folder you’ll see a file that should be named something like: XXXXXXX.default

Copy this file to your flash drive. You may need to compress it using a tool like 7Zip if it’s too large to fit on the flash drive.

Once it’s copied eject the thumbdrive and and take it back to the machine you just installed Thunderbird on.

Make sure Thunderbird is fully installed and then run Thunderbird for the first time.

Once it starts exit out immediately. Don’t enter any data or set anything up. By letting it run once it sets up all the folders you need in your Application Data folder which we can now replace with the file on your flash drive.

Once Thunderbird is closed, navigate to the same folder as you were at before (except on the new machine) and delete the XXXXXXX.default file you find in there.

Once it’s deleted copy the XXXXXXX.default file from your thumbdrive (decompress if necessary) into the folder.

Next Windows Vista and Windows 7 users should navigate to:

Windows Vista and Windows 7 navigate to the following location:


Windows XP users navigate to:

C:\Documents and Settings\Paul\Application Data\Thunderbird

Inside this folder you’ll find a file called profiles.ini.

Open profiles.ini using Notepad or your favorite text editor.

It should look something like this:







Change the value of XXXXXXX.default in profiles.ini to match the value of the original XXXXXXX.default file you copied from your flash drive.

Save the file, close all open windows and start Thunderbird.

If you’ve done everything correctly Thunderbird should start up without problems.

If you get an error saying something like: “Thunderbird is already running in another window“, then recheck the value of XXXXXXX.default in profiles.ini.

If it doesn’t match the original value then things won’t work and Thunderbird will keep throwing that error.

If  you originally created your signatures for your email accounts inside Thunderbird then you’re all done.

If, like me, you’ve got them saved as text files then you’ll need to copy them to the new machine and go into the account settings for each email account and make sure that it is pointing to the correct location for you signature files.

That’s it, you’re all done :)


  1. Bob R. says

    Thank you so much for posting this information. I had been to so many tech sites that claimed to have easy solutions for migrating Thunderbird from one PC to another but did not. The step by step process you provided worked like a charm.


  2. jim m says

    thanks for the migration procedure worked like a charm. i’m computer illiterate and still had no problem using your method. most of the other information i found on this job were complicated. yours was so easy even a caveman (me) could do it.

    BTW like the brain to mouth quote, been that way since birth and it causes problems…people don’t like the truth

  3. says

    Hi there, Thank you so much for your advice in migrating thunderbird. Your steps were very easy to follow and worked brilliantly.

    Some othere sites were so technical you needed a degree to understand it.

    So thanks heaps. Got it all done now and only took a few minutes.


  4. Teresa says

    Thank y0u so much for that. Even a technophobe like me could follow y0our steps easilly. You are a star!!

  5. Michael Pipe says

    Having scoured the universe for a solution to this problem, it was a relief to find a simple way that worked without the risk of a complete meltdown!


  6. rob says

    After much websearching, why has no one ever thought to do this before. Thankyou so much for taking the time to do this step by step instruction. was getting nowhere fast with every other search I have tried. Thankyou again. Rob

  7. Dustin says

    Got here thanks to Google. This is exactly what I needed! I’d done it before from XP to XP, but I wasn’t sure where to go with Win7. Thanks!

  8. Karl says

    Going from XP to W7 worked great and is so much easier than some other methods on the web, and it takes all the subfolders and email settings etc. all in one swoop! Thanks.

  9. Krish says

    I just migrated from Windows Vista to Windows 7. Thanks to your brilliant support notes I just moved from Thunderbird (with its all 5 email accounts) to the Windows 7 environment smoothly without any hassles.

    Thanks for your notes.

  10. Bob Ackerman says

    Well, it doesn’t work for me. I started when Thunderbird first came out and my folders are in my “My Documents” folder. There appears to be some configuration difference between my folder installation and newer versions.

  11. Kyle says

    Thanks so much for posting this. I found other how-to’s, but none worked or were as complete as yours. You’ve made my folks happy campers that I could migrate their email from one computer to another.

  12. Patricia Laurendine Ferrara says

    Great instructions! My contacts list is quite large, and rebuilding it manually was unthinkable. Thanks so much!

  13. Sarah says

    Thank you so much. Here is to HOURS of work that you just saved me. Really appreciate the clear cut step by step. I made the migration to Windows 8 without issue.

  14. Glen says

    That worked like a charm. No problems, not headaches. Just worked, which is very rare these days.
    Thank you so much Paul, a fantastic and easy to follow set of instructions.
    I didn’t even use Mozbackup as other sites suggest. Sounded like a real pain the backside.
    Your method is the best!

  15. Raymond says

    Just installed an SSD and needed to import my settings for Thunderbird and all of my emails. Thanks for posting this. Very useful and straightforward! Worked without any problems!

  16. Mick Florey says

    I just have to add that this is NOT easy if you have used different hard drives to install Thunderbird onto.
    e.g. XP pc was installed at D:Programsthunderbird and under Tools, account settings, Server settings (at the bottom: “local directory”)

    On laptop (I don’t have the same luxury of hard drive choice!), installed in same place D:Programsthunderbird, BUT tools, account settings, Server settings when checked came out as
    C:E:emailthunderbird…… so this got corrupted, as you can see, once this was fixed it all worked fine!

    BUT the secret, leave everything at default when installing. Its just that I like things organised and avoid C drive at all costs! :)

    What a pain this was!!

  17. Mick Florey says

    This works OK, unless you (like me!) have installed the original Thunderbird on another drive. (I hate installing programs to C drive)
    e.g. I installed on an XP machine at D:ProgramsThunderbird.
    I installed on a windows 7 laptop in the same location. (no problem)
    The difference being that under “tools”, “Account settings”, “server settings” local directory was set to E:emailthunderbird E: drive does not exist on my laptop!

    So, when transferred to the laptop and check this setting, it was actually: C:E:emailthunderbird
    As you can see, it got corrupted. I corrected this and (eventually) everything worked OK!!)

    To keep things easy, install with defaults!

  18. Natalie says

    Worked like a charm (going from Windows XP to Windows 8) even though I had previously installed and set up Thunderbird on my new computer (too eager). No problem overwriting with the profile info I copied from the old computer. As good as or better than having my own home IT department.

  19. Cindy says

    BRILLIANT!! This worked seamlessly, and as advertised, 10 minutes or less, and that was transfering from XP to 7. I had to do the same type of transfer for a Eudora holdout moving to Windows 7 as well, and it toko hours to fix the address box entries and mailboxes. SO THANK YOU!

  20. Rick says

    Like everyone else said this worked perfectly and is so fast. Thanks for the tip.

  21. Devan says

    WOW! Thanks so much for the info. I checked a couple of “expert” forums and all of them required extensions and programs. Seemed like a pain and the results weren’t looking good. Your steps took me maybe four minutes and worked perfectly! Couldn’t have been easier. Thanks for helping me with what my IT guy couldn’t!

  22. says

    Thank you so much you are savior, was wondering since last two days on how to import my thunderbird data to the new installation :)

  23. Jane says

    Wayne, I followed your directions to the letter and presto I now have Mozilla email on my laptop too. Thanks so much for your awesome directions and know how

  24. Gourav Sen says

    Paul it worked the first time, but once I closed thunderbird and reopened it none of my emails were there. I re-installed thunderbird and repeated the process again, but the same thing is happening. Can you suggest some measures??? Thanks.

  25. Mikey says

    I’m having the same issue Gourav Sen is. Copied the default folder and editing profiles.ini and it all showed up like a charm. But then it wouldn’t pull down new mail, and when I closed and reopened it, none of the mail appeared. The .default matches exactly in both places.

    • says

      If no mail is appearing then it sounds like you’re not deleting the .default (new installation) before copying over, or missing some other step.

      Without knowing your operating system, TB version etc, I just can’t tell. However, I can say, that, per user comments above, this solutions works for stock installs on XP, Vista, 7 and 8 when all steps are followed properly.

      More information might shed light on this.

  26. Mikey says

    Thanks for the quick response! No, I deleted the “new” default before copying over the old one. But this was a clean install of a new OS (Win7), would that be an issue? I’m using TB 17.0.7

  27. Al says

    Paul, you saved me a huge amount of work. Thanks a million for this. It worked like a charm for migrating T-Bird from XP to Win8. Took 10 min.

  28. Rob says

    Why couldn’t every other website I went to be this easy. Thanks a lot. Worked beautifully. You would think they could just add a “migrate” button or something.

  29. Mel says

    Oh my goodness, this completely worked – I have ben procrastinating because I have such bad memories of doing this on previous new computers. As you do it, it makes complete sende to me – THANK YOU so much

  30. Bob says

    Thanks Paul, that worked perfectly, I had a lot of trouble last time also, only took 15 min even with double checking everything on the way. :)

  31. says

    Even with my current version of Thunderbird, I was able to migrate easily from one machine running Win 7 Pro 64 bit to another running the same – although I did it over a network and skipped the USB stick 😉 Thank you, Paul, for keeping this post up three years later!

  32. Joe says

    Great tutorial, it went smooth and quick, moved email database from PC with Win XP to PC with Win Vista, the versions of the Thunderbird however were the same (v.24.0)

  33. Mary says

    Paul, a few years ago when I upgraded to Windows 7 I used “Windows Easy Transfer” to transfer all of my files, programs, and email, but the program did not transfer any of my email data from Thunderbird, so I lost it all. This time I made sure that I checked that I wanted my Thunderbird program data to be transferred, but all that transferred was the settings. I was so happy to find your solution on the internet. It worked like a charm for me. I had to do some research on the internet so I could find the files you were sending me to as just “search” did not work in the computer. It is amazing what solutions you can find on the internet. Thank you so much!

  34. Joe says

    Hi Paul,
    I want to migrate usernames and passwords, in Firefox, from one Win 7 hard drive to another. Should this process work? I have two storage drives on my computer. My plan is to make the newer larger one my C: and make the original C: a storage/backup. I attempted to migrate them using the process you describe here but it did not work for me.
    Thank You.

  35. Dan says

    Paul…. I have used your method with great success when migrating form one computer to another but I have a new challenge.

    Recently, my Win7 Pro machine suffered a drive issue and I lost the boot sector. All of my directories and files were intact and un-damaged so just built an new drive and copied all of the files over. The only thing I cant get to work is Thunderbird. Every time I load a clean version and copy the old to new, Thunderbird still insists on creating a new profile and ignores the one I just copied over with all of my data.

    Any thoughts or suggestions??

    • says

      Dan, I wonder if you’re actually starting Thunderbird and then quitting out of it before it creates a profile – before you copy your backed up files over?

      Make sure Thunderbird is fully installed and then run Thunderbird for the first time.

      Once it starts exit out immediately. Don’t enter any data or set anything up. By letting it run once it set up all the folders you need in your Application Data folder which we can now replace with the file on your flash drive.

  36. says

    Hi Paul. I also am among the success stories. Just a community college biology instructor with vast numbers of saved folders from Outlook Express, all of which got copied over and retained in Thunderbird when I loaded said software. When I migrated from my soon to be defunct XP system to my Vista laptop, everything made the journey successfully. But today I went to put email to a saved folder and almost fell out of my chair. All saved folders were gone … no where to be seen. My only thought is to do the migration again from my XP computer to the Vista computer. I’ll need to leave my XP computer intact as a back up.

  37. Mike says


    Thanks so much for your simple and very helpful instructions. After Windows Easy Transfer failed, your method worked flawlessly in transferring files from XP to W7.

    One quick question. It seems your method would be an effective and quick way to back up my Thunderbird files. Is there any reason your method would not work to back up Thunderbird files?

    Thanks. Mike

    • Fred Van Houten says

      That IS my Thunderbird backup method. Works great. I just let Laplink automatically back up the long-path-named file mentioned and I’m done. The restore, similar to Paul’s “new computer” procedure, also works. Are there other backup methods (that are halfway simple)?
      Regards, Fred
      PS I’m about to try Paul’s migration method now. Looks like it should work. It’s a big help for him to have outlined it here because the last time I did something like this was a couple of years ago and I forgot everything. Thanks, Paul!

  38. dave says

    HI and thanks for the info. I tried to go from windows 7 to windows 8.1 pro and everything went great until I got into windows 8 and there was no folders:


    C:Documents and SettingsPaulApplication DataThunderbird

    so now I am not sure where to put the XXXXXXX.default file?

    Can you help me out with that please Paul?


  39. Peter Gaywood says

    I’m trying to migrate my Thunderbird from an XP PC to a Win7 PC and I followed your instructions line by line,everything seemed to be going fine until I tried to open on Win7 PC. :'(

    It still wanted me to open a new account instead of transferring my existing one, so deleted every thing and tried again with the same result. I must be doing something wrong,j ust can’t figure it out .

    Can you suggest anything to help please – Thanks Pete

    • says

      It’s probably this part – which you perform BEFORE transferring the data the the new PC –

      Make sure Thunderbird is fully installed and then run Thunderbird for the first time.

      Once it starts exit out immediately. Don’t enter any data or set anything up. By letting it run once it set up all the folders you need in your Application Data folder which we can now replace with the file on your flash drive.

  40. Kent Agne says

    This looks like great info (confirmed by the positive comments). MY PROBLEM – I’ve already been up and running with Thunderbird on my new machine (a few months) and am just now getting around to this. My understanding is that the migration should have been done immediately. I’ve located the xxxx.defualt file on the old drive (actually a secondary drive on my new machine). Any suggestions as to how to add the old email and address book to the new Thunderbird profile. I’m almost certain that I’ve done this before, although it may have been done with another client (prior to using Thunderbird).


    • says

      I does, and it isn’t. I’ve been using 8 since the beginning and really, really like. It’s stable, fast and despite some issues with Metro is a really great OS. 8.1 fixed a lot of those Metro issues and future releases will improve it even further.

  41. Fred says

    Re the third paragraph of your text above: Now that your migration is complete – do you now just process email on your second computer or can you go back and forth between the 2 computers’ TBird installations at will?
    Thanks, Fred

    • says

      Fred, Yes you could and should go and forth especially if you are an IMAP user and want changes replicated on all machines (which is not as good an experience with POP3).

  42. Fred says

    Hi, Paul. I followed your instructions for Windows 7 up to where I delete the xxxxxxxx.default file from C:\Users\[Username]\AppData, etc.
    Under the [Username] There is no AppData folder name showing here (only Contacts, Desktop, Downloads, etc.).
    I noticed there is a pic of a padlock next to the [Username] folder.
    This seems to be related to “Share with Nobody”; but I can’t get that status to go away.
    When I try to change this, a lot of file names whiz by on the screen, including many which say “[Username]\AppData\[etc.]. Go figure.
    Any ideas?

    • Fred says

      To answer my own question, I discovered that ….AppData.. etc. was hidden for some unknown reason. To unhide it, I had to do Start, Control Panel, Appearance and Personalization, Folder Options, View (tab), Advanced Settings (box title), Hidden Files; then check “Show hidden files, folders and drives”. Simple, huh? Thx for listening! Fred

    • Fred says

      Hi again. Once I figured the above out, your instructions worked perfectly in a few minutes. Thanks a bunch, Paul (and sorry for the verboseness)!