It is wise that you copy the files from the bad disk to a working location that is NOT in use by the current Tbird installation. This way, you don't have to rename and replace stuff and possibly breaking things further. If you can copy ALL of the profile folder from the bad disk without read errors or any other issues, that would be better and would give you a fully functional profile that you can load and use to compare with the outdated profile from the same Thunderbird installation.

It is wise that you copy the files from the bad disk to a working location that is NOT in use by the current Tbird installation. This way, you don't have to rename and replace stuff and possibly breaking things further. If you can copy ALL of the profile folder from the bad disk without read errors or any other issues, that would be better and would give you a fully functional profile that you can load and use to compare with the outdated profile from the same Thunderbird installation.

It is wise that you copy the files from the bad disk to a working location that is NOT in use by the current Tbird installation. This way, you don't have to rename and replace stuff and possibly breaking things further. If you can copy ALL of the profile folder from the bad disk without read errors or any other issues, that would be better and would give you a fully functional profile that you can load and use to compare with the outdated profile from the same Thunderbird installation.

I am not able to copy the Thunderbird files from the bad disk without read errors, so the suggestion from Stans is not a possibility. The only way I know of to view the files from a disk that will not boot is by using Thunderbird to access those files, and the only way I can see for me to do this is by having access to the folders from both bad and the new disks so that the messages can be copied.

Are you able to connect the bad disk to computer as an external hardrive, so you are not booting from it?

If yes, hopefully the mbox files containg emails will not have errors.

Exit Thunderbird.

Access .default\Mail\Local Folders folder on the bad disk.

You should see mbox files (no extension) and .msf files (indexing files). You may also see folders with .sbd extension. They contain subfolders and so may also have mbox files.

The mbox files (no extension) contain emails. You can copy those mbox files and paste them into the current Thunderbird .default\Mail\Local Folders folder.

Have you tried running Chkdsk to see if you can then get access to those files? Or running sfc /scannow from the command prompt ?

• https://www.online-tech-tips.com/windows-10/check-disk-and-system-files-in-windows-8-10/

Thanks to Toad-Hall for the suggestions, but you don't seem to understand. The bad disk is VERY bad. Win 10 went thorough diagnostic and repair procedures at least a dozen times before it gave up. Even though Smart was enabled to check for signs of a failing disk, it gave me no clue that there was a problem with the disk. I kept assuming this was a Win 10 problem, because that is what Windows kept telling me. (I could not get the system to boot, so Windows was the only tool I had to diagnose the problem.) There are countless fragments of files that have been recovered from the attempts to use software to repair the disk.

Since I recovered the system from the backup, I have continued to use the system. I can't replace all of the files with thousands of known good messages with the corrupted files from the bad disk. If you read through the question I am asking, you will see that I need to _extract_ the messages that can be recovered from the bad disk. I have read access to the bad disk, but how can I select the messages in the Thunderbird files on the bad disk so I can copy them?

With all of the help articles we have for Thunderbird, I am surprised that I could not find an article on recovering messages and other Thunderbird files from a bad disk. This must happen fairly frequently.

Is it necessary to pay someone to get answers to questions like this about the internal operation of Thunderbird? If so, how can I find that person?

I would greatly appreciate any help.

Here's what you don't understand. The success in retrieving your messages and contacts from the bad disk depends on you being able to read/copy/retrieve the mbox and mab files from that bad disk. If this is not possible because of read errors, then there is no other way around it. Thunderbird doesn't have any hidden or secret capabilities to read those files from a bad disk. There is a detailed help article here on Thunderbird help, that covers how to migrate your Thunderbird data from one computer (disk) to another and where Thunderbird stores its data, but NONE of them covers doing so from a bad, inaccessible disk. You seem to think there is somehow a way for Thunderbird to successfully read data from a bad disk when normal access to that disk is not possible because of read failures. A bad disk is bad system-wide. It is illogical to expect Tbird to be able to access that disk when Windows (File Explorer) itself is unable to do the same. Thunderbird doesn't bypass Windows to access the disk. It relies on the underlying provisions of Windows (the Operating System) to access the disk, and it seems you think Windows complaining about the bad disk does not somehow affect Tbird's access to the disk. The files you want from the bad disk are stored in the location discussed here https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

As Toad-Hall stated, let's hope those mbox files, where Tbird stores your messages, are accessible/readable from that bad disk without errors. If those files cannot be retrieved intact (in whole without errors), then there isn't much you can do to retieve those messages. Thunderbird will most likely hang or crash if you attempt to make it read the unreadable/corrupt/error-prone mbox files.

If you have run both Chkdsk and sfc /scannow from the command prompt and Windows was unable to fix read errors then no program can access it.

Sometimes the OS cannot boot from a disk due to read errors in the files and folders that are required to run the Operating System, but sometimes it is possible to extract other non OS specific individual files. You would need to install the OS onto a new disk or change the BIOs to boot from a different source and use that to boot up computer. If you remove the bad disk and access the bad disk using it as an external hardrive and copy single files then it is possible to recover data, so that Thunderbird can access them. A read disk error can mean a fault in the disk or in the cables that connect to disk, hence why I suggested you remove the disk and try to access as external hardrive. There are various visual aids using YouTube, but if you cannot access the bad disk when it is used as an external hardrive, then you will need to try specialist recovery software and see what can and cannot be extracted.

Ordinary programs like Thunderbird will not be able to read from a bad disk if Windows cannot access them because the programs communicate with operating system in accessing files.

The info I gave, told you about the specific individual files that contain emails so you could manually extract them. So at least you know which files contain the emails.

The 'Personal Address Book' is called 'abook.mab' and the 'Collected Addresses' is called 'history.mab'. Both of these files are in the 'profile name' folder which is usually called 'xxxxxxxx.default' where the x's are letters and numbers. Both of these files can be copy pasted into a different 'profile name' folder replacing the default blank files of same name.

Stans and Toad-Hall, I appreciate your efforts, but it sounds like you really don't understand, and I don't know how to express the problem more clearly without repeating myself. Would either of you be willing to speak to me on the telephone so that we can focus separately on each specific aspect of the problem? I live in Austin Texas USA, and it appears that Toad-Hall is in the UK. My schedule is flexible enough to be available any time of the day or night that is convenient for either of you.

I sounds to me like you might have read the subject line of the question but not anything other than that. Or perhaps you could be answering easy questions that I did not ask because you are not able to help with the real problem? Or could each of you be basing your advice on the other's posts instead of the original problem? I don't know.

I see that there is an option for a private message on each person's profile. Would either of you be willing to exchange phone numbers and arrange a time using private messages?

Many thanks... Lloyd

None of us is going to call you, but we should be able to properly communicate here in the public forum, and not via private messaging. By all means explain what the real problem is and what it is we don't understand, and point out those hard questions that we're not answering.

As I understand it:

C: drive with Windows OS failed to boot. It had read error issue. You got a new disk formatted as C: drive to replace bad C: Drive and now have Windows OS running from new disk.

You asked: Is there a way I can copy the files with the messages from my bad hard drive

Answer: Yes, if you can access the bad hard drive.

You asked: The bad disk shows so many read errors that I don't want to simply move the files from the bad disk into my new disk. I want to copy only the messages that are new since that last backup.

Answer: Individual messages in separate files do not exist. Mbox files (no extension) will have the same name as the folder name you would see in the Thunderbird Folder Pane. So a single mbox file contains many emails. If you can access bad disk then you can copy (not move) specific files and paste them into current profile > Mail > Local Folders, but this must be done via profile name folder and Thunderbird must not be running. You can edit the mbox file eg: 'Inbox' can be renamed as 'OldInbox'. In exactly the same way that any file can be renamed.

But all this advice of copying of specific files from bad disk is moot if you cannot even access the bad disk.

Q: Are you now connecting the 'bad disk hard drive' to your computer as if it was an external hardrive using a usb to sata/ide adapter kit?

Q: If yes: Are you able to access that 'bad disk' and see it's contents ?

Toad-Hall, Yes! That is my problem! Thank you.

First, to answer your questions, I have no problem accessing the bad drive. (The motherboard supports 8 SATA devices. I left the bad drive in the computer and re-assigned it as W:.)

Browsing the bad drive with Win File Explorer, nothing major appears to be out of order, except for the directory named found.000, which contains 177 directories, and each of those directories contains files that were apparently recovered as a result of the many attempts by Win 10 to repair the disk. I don't notice anything that looks unusual about files in the Thunderbird directories, although I don't know how most of them are used.

When I have had problems with Thunderbird over the years, and I have spent enough time browsing the Thunderbird directories in plain text to have a vague understanding of where various info is stored (the messages, address books, addons, etc.). I see patterns in the file names and types that are in the "Local Folders" directory, and it appears that the procedure for renaming a folder to avoid duplicates would be more complex that just renaming an individual mbox file. At least, I am not confident enough so I would have wanted to take the risk of experimenting with them.

I see directories with the type of .sbd that correspond to subdirectories of folders. I see pairs of files with the same name that correspond to the individual folders, and each of those pairs has a file type .msf and file without an extension (Mbox?).

I assume that I will have to rename all of the files and directories in ...default\Mail\Local Folders to avoid duplicates when they are copied to the new drive. I assume the files and subdirectories within the .sbd directories would not need to be changed.

Do you have enough knowledge of the internal operation of Thunderbird to be confident that you can tell me exactly how to rename these folders?

Thanks so much for your help!

Like I said before, don't bother with renaming anything, you'll just mess things further and add to your frustrations. Create a folder on your new/good disk in a convenient location that is not already in use by Thunderbird, say the Desktop, then copy the entire Thunderbird folder from the bad disk (W:) into that folder. If copying the entire folder is not possible because of read errors, try to copy the individual mbox files, one at a time so that you recover as many of those as you can. The desired result is to have a copy of those mbox files somewhere else other than on the bad disk, and to have them intact (not corrupt). Once you have them, we'll guide you on how to browse and extract the messages they contain, since the mbox files contain multiple messages. For example, the Inbox folder in Tbird has a corresponding mbox file named Inbox (without extension) inside the Mail subfolder (for POP accounts) and inside ImapMail subfolder (for IMAP accounts). Ignore the msf files, those are simply index files used for indexing the contents of their corresponding mbox files. The addresses are stored in mab files named like abook.mab and history.mab. Copy those over as well.

re :I see pairs of files with the same name that correspond to the individual folders, and each of those pairs has a file type .msf and file without an extension (Mbox?).

Yes you are correct. The .msf files are index files used by Thunderbird to access the actual emails held in the mbox file (no extension) of same name. So, it is the mbox file (no extension) that contains the emails.

re: I see directories with the type of .sbd that correspond to subdirectories of folders.

Yes these *.sbd folders will probably contain more *.msf files and mbox files which are the subfolders.

The following is a hyperthetical example of how to get a copy from bad disk to desktop, rename and paste renamed files into thunderbird profile folder in the 'Local Folders' folder.

Let's pretend you have : In Folder Pane you have a folder called 'Staff' and it contains two subfolders called 'Staff A' and 'Staff B'. But the bad disk also has these folders and you need to get a copy so you can compare contents but do not want to overwrite any folders.

In Profile folders, you would see a folder called 'Staff.sbd'. You will also have 'Staff' (mbox file) and 'Staff.msf' (index file). This is because in order for Thunderbird to know about 'Staff.sbd' so it can display the subfolders, it needs both the mbox and index files of same name to create the top level folder called 'Staff'.

'Staff.sbd' will contain 'Staff A' (mbox), 'Staff A.msf' and 'Staff B' (mbox) and 'Staff B.msf'.

• Create a folder on Desktop and call it 'TB Temp'.
• On bad disk...You will need to copy 'Staff' (mbox) and 'Staff.sbd' (do not worry about the .msf file as Thunderbird will recreate index files.)
• Paste 'Staff' (mbox) file and 'Staff.sbd' folder into 'TB Temp' folder on desktop.

In the 'TB Temp' folder you will now see 'Staff.sbd' and 'Staff ' (mbox)

• Right click on 'Staff' (mbox) and select rename and change to 'OldStaff'
• Right click on 'Staff.sbd' and select rename and change to 'OldStaff.sbd'

Note: it is vital you make sure those names are identical as shown in bold.

You do not need to rename the files contained in 'OldStaff.sbd' because different top level folders can contain folders of same name.

• Exit Thunderbird if it is running.

• In the 'TB Temp' folder on desktop, copy the 'OldStaff.sbd' folder and the 'OldStaff ' (mbox no extension) file.
• Access profile name folder, click on 'Mail' folder, click on 'Local Folders' folder to see contents.
• Right click in area in 'Local Folders' folder and select 'Paste' to paste the copied folder and file into the 'Local Folders' folder.

When you start Thunderbird, in 'Local Folders' mail account you will see 'OldStaff' folder and it will contain two subfolders called 'Staff A' and 'Staff B'.

On bad disk, you may have some mbox(no extension) files that do not have a same name .sbd folder. These are top level folders without subfolders. You can use the same process to copy to desktop folder 'TB Temp', rename and then paste renamed file into 'Local Folders'. Just remember, Thunderbird must not be running whilst doing anything in the 'profile name' folders.

I would like to say that if the Thunderbird profile worked perfectly ok prior to disk going bad, that profile may be fully intact and would contain all emails, address books etc etc up to that date when last used.

Stans advice on attempting to copy the Roaming 'Thunderbird' folder and replace the current Thunderbird folder with copied version could put you back to your original position, so you would not need to compare anything. It would be in effect using the bad disk version as your backup. This of course assumes there is no read error issues in all of the Thunderbird folder including all folders and files.

However, if that is not possible or you would still prefer to keep the current profile and just go through the process of copying over renamed files to compare results, then my comment would show you what to do to recover files containing emails.

The 'abook.mab' and the 'history.mab' files cannot be renamed. But you can copy them and paste them into the current profile overwriting the default empty files of same name.