I'm using Windows 11, not Windows 10. Thanks.

How do I make a backup copy of my Thunderbird email client, saving all the subfolders?

https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile

I would like to then uninstall Thunderbird and then reinstall it, as a new user, and without losing any of my old user folders.

What are you trying to achieve in the first place? All your data such as messages, passwords and user preferences, and changes made while you use Thunderbird, are stored in a special folder called a profile. Your profile folder is stored in a separate place from the Thunderbird program, so that if something ever goes wrong with Thunderbird your information will still be there. It also means that you can uninstall Thunderbird and reinstall without losing your settings and data.

Having said that, typically Thunderbird is installed once with Administrator privileges. So it's available for all users on a computer. Do you want to use Thunderbird as another user, and use an existing profile for that other user? Then you don't need to re-install Thunderbird on that computer. All you need to do is to start Thunderbird once as the new user, and close it right after. That will create a new empty profile for that user. Then copy over the contents (i.e. all files and folder) of the existing profile to the newly created profile folder for the other user.

Also see https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

Thanks Christ1, What are you trying to achieve in the first place?

I currently have a webpage hosted by Network Solutions, and I use Thunderbird to download all my email messages from that internet provider for storage on my laptop. But I never want to erase any of these messages from the Network Solutions server or my laptop. I recently paid for 25 gigabytes of their bandwith and it's now more than I'll need for a lifetime.

A problem arose because I originally had only 2 GB storage at Network Solutions, and I thus erased a year's worth of "sent" messages, in order to keep enough storage on their server. It was a ridiculously stingy setup that I was ignorant of. The problem was that on my Laptop TBird client, all those "sent" messages that I erased from Network Solutions were also erased from my TBird laptop folders and are now irretrievable. I think the reason was because I had a "POP" or "IMAP" configuration, and I wasn't aware that those messages would be erased on my laptop.

So I'd like to (1) save all my TBird user files (there are a few of them), and I'd like to reload TBird as a new user with the configuration that will prevent losing any email messages ("inbox," "Sent," "Drafts," "archives," etc.) on either my laptop or my NetworkSolutions server. Should I use POP or IMAP? Can you please guide me step by step? I would occasionally want to reload one of my previous TBird user accounts to find old email messages, then of course, switch back to my new user account. Is that very difficult to do?

I hope this is clear enough and it shouldn't be too difficult. Please let me know if you need to know more. Again, many thanks. When you say, "Your profile folder is stored in a separate place from the Thunderbird program," does that mean that this folder is already backed up and there's no way it can be erased unless I erase it? Can the POP or IMAP configuration erase it? Are you saying that I can simply re-install the latest version of TBird and all those previous user folders will automatically be backed up and not be erased? Do I first have to uninstall the existing TBird version?

When you say, "Then copy over the contents (i.e. all files and folder) of the existing profile to the newly created profile folder for the other user," can you please tell me the file location of this existing profile? I apologize for my ignorance on these matters and thanks again. I'll study the link you provided.

A POP account will download the inbox and keep separately from the account. IMAP accounts sync the messages on PC with the messages on server. Deleting from the PC causes the message on server to be deleted. IMAP achieves what you want, so long as you don't delete the messages. You then have all on both. Either can work.

all those "sent" messages that I erased from Network Solutions were also erased from my TBird laptop folders and are now irretrievable.

Didn't you create backups of your Thunderbird profile? I suppose you now know why backups are important. Note, with IMAP you would need to turn on synchronization, which is Thunderbird speak for downloading an offline copy of all your messages on the server to your local disk . https://support.mozilla.org/kb/imap-synchronization

I think the reason was because I had a "POP" or "IMAP" configuration

It's not "or". As per your description you should have an IMAP account. But you should stop guessing, and check it yourself. At the top right of the Thunderbird window, click the menu button ≡ > Account Settings > Server Settings

I'd like to (1) save all my TBird user files

What exactly are "TBird user files"? If you want to backup all your Thunderbird data (a.k.a. the Thunderbird profile) - see above.

I'd like to reload TBird as a new user with the configuration that will prevent losing any email messages ("inbox," "Sent," "Drafts," "archives," etc.) on either my laptop or my NetworkSolutions server.

I don't see what problem a new Windows user is supposed to solve. Of course you can do that, but what for?

Should I use POP or IMAP?

Regardless of which protocol you want to use, your only insurance for data loss are backups created on a regular basis. If you want to set up a new POP account, all you get from the server is Inbox. You'd have to copy all your other stuff from the server manually to a new POP account. However, you already have an IMAP account with all your (remaining) data readily available. So all you'd need to do is to turn on IMAP synchronization for the IMAP account if not done yet, and create backups on a regular basis. Job done.

When you say, "Your profile folder is stored in a separate place from the Thunderbird program," does that mean that this folder is already backed up and there's no way it can be erased unless I erase it?

Backups of the Thunderbird profile are not created automatically. It is your responsibility to do this. As stated before, backups will ensure you can recover your data in case of data loss, for whatever reason. And trust me, there are many possible reasons why data loss can occur.

Are you saying that I can simply re-install the latest version of TBird and all those previous user folders will automatically be backed up and not be erased?

Nothing is backed up automatically. But re-installing the application will not erase the profile, unless you explicitly tell it to do so.

Do I first have to uninstall the existing TBird version?

I have no idea why you want to re-install TB in the first place. Feel free to do it, but you'd be wasting your time.

can you please tell me the file location of this existing profile?

It's something you need to find out, and it was already mentioned above. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

David and Christ1, thank you. I must apologize because I recently got off narcotic pain meds and my brain was very foggy. But now I think I understand. Please correct if I'm wrong.

1) How to make a Backup:

Here is the local folder that contains all 14 of my profiles:

Users\tsbto\Appdata\Roaming\Thunderbird\Backups\Profiles >20j3k319.Lenovo 1 >20j3k319.Lenovo 1 - Copy >bswex22m.default-release >bswex22m.default-release - Copy - - - PLUS 10 more Folders (some are copies, some are defaut, and some are others) - - -

I put copies of these 14 sub-folders into the "Backups" folder shown above, and I left the originals in the "Profiles" folder.

2) With these profile backup folders, I believe I can change from profile to profile by substituting one folder for another. Again, I want to be certain I do not accidently delete any user folder or its messages either on my Laptop TBird program nor on my web server at www.networksolutions.com. (Intentional deletion would be different.)

I got David's note to "synchronize," and I'll do that next, being sure to eliminate any option that would prevent a one-to-one mapping between the messages on my Laptop and those on my www.networksolutions.com server. (Again, intentional deletions are different.) And I now understand I don't need a "fresh" re-install of TBird.

Many thanks, Tom

David and Christ1, thank you. I must apologize because I recently got off narcotic pain meds and my brain was very foggy. But now I think I understand. Please correct if I'm wrong.

1) How to make a Backup:

Here is the local folder that contains all 14 of my profiles:

Users\tsbto\Appdata\Roaming\Thunderbird\Backups\Profiles >20j3k319.Lenovo 1 >20j3k319.Lenovo 1 - Copy >bswex22m.default-release >bswex22m.default-release - Copy - - - PLUS 10 more Folders (some are copies, some are defaut, and some are others) - - -

I put copies of these 14 sub-folders into the "Backups" folder shown above, and I left the originals in the "Profiles" folder.

2) With these profile backup folders, I believe I can change from profile to profile by substituting one folder for another. Again, I want to be certain I do not accidently delete any user folder or its messages either on my Laptop TBird program nor on my web server at www.networksolutions.com. (Intentional deletion would be different.)

I got David's note to "synchronize," and I'll do that next, being sure to eliminate any option that would prevent a one-to-one mapping between the messages on my Laptop and those on my www.networksolutions.com server. (Again, intentional deletions are different.) And I now understand I don't need a "fresh" re-install of TBird.

Many thanks, Tom Note: I swear I posted this response before but it must've gotten erased???

Here is the local folder that contains all 14 of my profiles:

14 profiles? And even if half of them are just copies, that would still leave 7. What are these for?

I believe I can change from profile to profile by substituting one folder for another.

Not sure what that means. In any case, you can tell Thunderbird with which profile to start:

thunderbird.exe -P "<profile_name>"

... being sure to eliminate any option that would prevent a one-to-one mapping between the messages on my Laptop and those on my www.networksolutions.com server.

You cannot avoid that as long as your account is IMAP. This is simply the way IMAP works. And it has got nothing to do with IMAP synchronization. As stated before, your protection against whatever kind of data loss are your profile backups.

I swear I posted this response before

You did.

With these profile backup folders, I believe I can change from profile to profile by substituting one folder for another.

you can tell Thunderbird with which profile to start: thunderbird.exe -P "<profile_name>"

Another way to switch among profiles that is easier than moving folders around the file system is Help menu > Troubleshooting information > about:profiles > click "launch" or "set as default" next to the desired profile.

I assume that Thunderbird expects all profiles to be in the default location, but I do not know.

Christ1, David, and Rick, I think I finally got the gist of this, even though I sometimes use the wrong terminology and can be confusing to those more knowledgeable than me.

I don't know why my posts seem to have disappeared, but then came back.

Anyway, I'll mark this as a complete response to my question and express great thanks for the people here and others behind TBird.

Best, Tom

In case a summary is helpful: I believe that you want to use one profile that has all your messages, and as David said, IMAP and, if you don't want any messages to be deleted, don't delete them. Then all your messages will remain on the server and in Thunderbird, even if you file them in many folders in that account.

Also: your posts may have been held for moderation, then published after you re-wrote them. Maybe your brain wasn't foggy after all.  :)

Good luck.