This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Transfering Thnuderbird data to new PC

more options

1) I have Thunderbird 78.5.0 on my five-year old Windows 10 laptop and want to copy my data files to my new Windows 10 HP desktop pc.

2) I read and followed the directions in "Moving Thunderbird Data to a new Computer". I tried it several times, but I could not get it to work. Each time I pasted in the files, but when I opened Thunderbird, the new account window came up and none of my data was there.

3) I read the article "No Success with Moving Thunderbird Data to a New Computer" and tried the method on appuals.com using MozBackup as described on appuals.com. That program indicated a corrupt file, so again, unsuccessful.

4) I tried to download the Restoro Repair app from appuals.com, but my anti-malware program gave a warning, so I aborted.

5) I read the article from MozillaZine on "Move to a New PC", but nothing I tried from there worked either. I started with downloading the more recent MozBackup version, but I still got the corrupt file message. I also tried moving pieces of the profile file as directed, but then Thunderbird was unable to open at all.

6) I deleted the Thunderbird app from the desktop and downloaded another copy, which I am ready to install. However, I still need help on moving the data!

1) I have Thunderbird 78.5.0 on my five-year old Windows 10 laptop and want to copy my data files to my new Windows 10 HP desktop pc. 2) I read and followed the directions in "Moving Thunderbird Data to a new Computer". I tried it several times, but I could not get it to work. Each time I pasted in the files, but when I opened Thunderbird, the new account window came up and none of my data was there. 3) I read the article "No Success with Moving Thunderbird Data to a New Computer" and tried the method on appuals.com using MozBackup as described on appuals.com. That program indicated a corrupt file, so again, unsuccessful. 4) I tried to download the Restoro Repair app from appuals.com, but my anti-malware program gave a warning, so I aborted. 5) I read the article from MozillaZine on "Move to a New PC", but nothing I tried from there worked either. I started with downloading the more recent MozBackup version, but I still got the corrupt file message. I also tried moving pieces of the profile file as directed, but then Thunderbird was unable to open at all. 6) I deleted the Thunderbird app from the desktop and downloaded another copy, which I am ready to install. However, I still need help on moving the data!

Chosen solution

Apologies for getting your name wrong earlier, Matt. Don't know what I was thinking. I realized that the deleted folders might be in the Recycle bin. I found them and restored them, so now Thunderbird opens. I will try your instructions and see how that works out.

Read this answer in context 👍 0

All Replies (4)

more options

removing and reinstallig does nothing about existing profile data. So get your head around that first up.

Second install and start Thunderbird it will startup the existing default profiile.

Go to the troubleshooting information on the help menu and click to show the profile folder. Close Thunderbird once you are in the profile folder. Go to your backup and open whatever folder contains prefs.js. Copy the entire contents of that profile folder over the one that Thunderbird opened and acknowledge the replace messages. If you get no replace messages you almost certainly are copying the wrong thing to the wrong place.

Restart Thunderbird and your mail and address book should be there.

more options

Thanks, Mark. I reinstalled Thunderbird but immediately ran into a problem. Instead of starting, I get a message: "Profile Missing. Your Thunderbird profile cannot be loaded. It may be missing or inaccessible." The reason why I uninstalled and reinstalled was because the last method I tried involved deleting the files and copying in the ones from my old computer that I want to use. Since Thunderbird wouldn't start, I looked up "Finding your profile without opening Thunderbird" and followed the steps. It looks like the two folders I copied into the Profile folder yesterday are still there, even though I uninstalled. I tried copying over the default folder, but I get the same "Profile Missing" message. My intention with the uninstall/reinstall was to get back to an original, pristine copy of Thunderbird, but that did not happen. Looks like I messed things up more. I hope you have a suggestion on what I should do now.

more options

Chosen Solution

Apologies for getting your name wrong earlier, Matt. Don't know what I was thinking. I realized that the deleted folders might be in the Recycle bin. I found them and restored them, so now Thunderbird opens. I will try your instructions and see how that works out.

more options

Success! Thunderbird opened immediately to my emails, all the folders are there and so are the address books. Your method turned out to be the simplest I came across. I wish I had seen it first. Thanks so much, Matt!