Not sure what you mean by "I tried to get Thunderbird to use that profile, but no luck." If the problem is that you couldn't figure how to tell Thunderbird to use the right profile, the relevant information to do that can be found in the following article, although what exactly needs to be done to accomplish what you need may not be very clear:

https://support.mozilla.org/kb/profile-manager-create-and-remove-thunderbird-profiles

Basically, you choose Help > Troubleshooting Information from the menu bar, then click about:profiles in that page to open the About Profiles page. You may manage your profiles there. To make the one you want the default, click the Set as default profile button under it.

So ... I go ahead and download Thunderbird prior to this? Do I set up a "new account" first, then change the profile? I appreciate the reply, and I'll look again at the help article, but the exact steps to make this work ... including downloading and setting up a "new" account are not clear to me.

OK, I was merely referring to the available documentation, but I'm seeing how it may be confusing, so I'll be sure to provide more details from now on…

First off, you need to differentiate a profile in Thunderbird from a profile folder in the filesystem, which is the folder where the profile data is stored. A profile is not an account, it's just some sort of reference to the profile data. When you tell Thunderbird to use a different profile, you point it to a different profile folder where all your mail and account settings are stored.

A profile you don't use may exist in Thunderbird without the corresponding profile folder if that folder has been deleted. And you may also have a profile folder that's not associated with any profile in Thunderbird if you've copied the folder from elsewhere.

What you have and are trying to bring back to Thunderbird is a profile folder. In order for Thunderbird to use it, you have to associate it with a profile in Thunderbird. That's why you have to create a new profile (not a new account) in Thunderbird, so you may be able to point Thunderbird to the profile folder you have.

The instructions to do that given in the documentation I linked seem unnecessarily complicated, indeed, and I'm not sure whether it's because they're outdated or because I'm missing something. They talk about using an external tool to do something that seems can be easily done from within Thunderbird using the 'About Profiles' tab…

Basically, all you have to do is create a new profile and either associate it with the profile folder you have during the profile creation process, or alternatively, let a new profile folder be created when you create the profile, then (quit Thunderbird first if you do this) replace the contents of that new profile folder with the contents of the profile folder you want to use.

Hope that makes things clearer and helps you solve the problem.

Thanks David. Forgive my denseness! Here's what I've done. I have a folder from a backup of the entire Profile folder from my old drive. I know it contains the right info b/c I see the names of folders when I transfer to a thumb drive. I first deleted everything on my computer having to do with Thunderbird ... application and all files I could find. I then downloaded Thunderbird and installed it. In so doing, I had to fill in the info for a POP 3 account; i.e., incoming server, port, email address, password, outgoing server and port. When I did that, the application opened. I immediately closed the app, and went to the place under C://Users/AppData/Roaming/Thunderbird/Profile (folder). I opened the Profile folder and deleted everything in it. I then copied the contents of my backed up Profile folder and pasted all those contents into the Profile folder mentioned above. When I then opened Thunderbird, I got a message saying "Missing Profile. Your Thunderbird profile cannot be loaded. It may be missing or inaccessible." What did I do wrong? Thanks for sticking with me!

Ah, I see. You did nothing wrong, you just don't know how to finish the restoration process you started. The part you're missing is what I said in my previous reply, i.e. you have to associate each of the profile folders you have (within that Profiles folder) with a profile in Thunderbird.

Thunderbird didn't automatically do that when you restored the Profiles folder because you didn't include in the backup a file called profiles.ini that's stored within the Thunderbird folder, together with the Profiles folder. That's where the list of profiles and the folder associated with each of them is stored. Since you didn't restore that file (because you didn't include it in the backup), Thunderbird has forgotten the profiles you had, and you have to create new profiles to tell Thunderbird where to find the profile folders that you have.

You could fix that by manually editing the profiles.ini (text) file, but I would rather do it by creating new profiles from the About Profiles tab in Thunderbird, associating each of the profiles you create with the corresponding profile folder you have in your Profiles folder, which you can do by using the Choose Folder button that appears when you start the profile creation process.

David, you probably think I've never even booted a PC. I'm still in the dark a bit, specifically about how to do: " I would rather do it by creating new profiles from the About Profiles tab in Thunderbird, associating each of the profiles you create with the corresponding profile folder you have in your Profiles folder, which you can do by using the Choose Folder button that appears when you start the profile creation process."

I went to the "about profile" tab and saw several items. I think I understand that somehow I need to insert my old (backup) profile FOLDER inside the "Thunderbird" folder under User/AppData. I also need to have a profile.ini file in that Thunderbird folder as well. Also, I think I understand that the profile.ini must somehow "match" the profile folder that I have backed up on a thumb drive. I don't know how to make this match. Would you be so kind as to assume I know NOTHING about the paragraph of yours that I copied/pasted above and lead me through it? (Your assumption would be correct!) I'm sure this is a simple thing, but it would sure be nice if there was a set of specific instructions on the forum. Thank you!

My understanding was that you had already put a copy of the Profiles folder you had previously backed up into the AppData/Roaming/Thunderbird folder on the new hard drive, overwriting any Profiles folder that Thunderbird might have created there when you launched it for the first time. If that's not the case, you need to do that now (quit Thunderbird first if it's running), although a better way to accomplish the same would be to copy the contents of that folder, i.e. copy the individual profile folders within that Profile folder into the already existing Profile folder, in order to not overwrite the new default profile folder that Thunderbird created there and thus avoid Thunderbird complaining that it cannot find the only profile it knows about until we fix this.

As to the profile.ini file, I mentioned it just so you could understand that all this trouble is a consequence of not having included that file in the backup, but you may forget about that file now, we'll fix this from within Thunderbird.

So assuming your old profile folders are already within the AppData/Roaming/Thunderbird/Profiles folder, launch Thunderbird and proceed as follows:

1. Choose Help > Troubleshooting Information from the menu bar.
2. Click about:profiles in that page to open the About Profiles page. This is basically an enhanced built-in version of the (outdated) Profile Manager that the KB articles talk about.
3. Click the Create a New Profile button to create a new profile and click Continue.
4. Name the profile however you want and click the Choose Folder button to choose the profile folder within the Profiles folder (from the backup) that you want to associate with this profile.
5. Click Done.

You can now (finally! :)) tell Thunderbird to switch to that profile or set it as the default. Repeat the process for each of the profile folders from the backup you want to associate with a profile in Thunderbird.

Forgot to mention that the procedure I suggested was meant for the general case where you'd want to restore several profiles you might have before. If you only have 1 profile to restore, as is usually the case, a simpler way to fix the problem would be to reuse the new default profile that Thunderbird created.

You could do that by just replacing the contents of the new default profile folder with the contents of the profile folder you want to restore (or alternatively by changing the name of the profile folder from the backup to be the same as the name of the newly created default profile folder, then overwriting the latter with the one from the backup). That procedure can only be used to restore a single profile, but if that's all you need, you wouldn't have to create any profiles doing things that way…

Aaand… I'm realising now that it isn't clear whether you still have the new default profile folder that Thunderbird created the first time you launched it… Some of the things you said would seem to indicate that you don't, as that's what would have caused Thunderbird to show the "Missing Profile" error message that you said you got at first… But Thunderbird would refuse to launch if that was the case and you said in a later post that you "went to the about profile tab and saw several items", which would imply you're able to launch Thunderbird nonetheless…

So can you launch Thunderbird or not? If you don't (because Thunderbird cannot find the default profile folder) then, before you can do anything else, you'll have to do one of the following:

• Edit profiles.ini to replace any reference to the profile folder that no longer exists with the folder you want it to use instead. This would solve the whole problem if you only have one profile to restore, btw.
• Delete profiles.ini, so Thunderbird creates a new default profile (and asks you to set up a mail account) again.

You have been patient and very helpful. However, I'm having no luck making this work. Perhaps tomorrow I can send a couple of screen shots showing the contents of my backed up Profiles folder and screenshots of what I see in the "about profiles" tab in Thunderbird. I feel like I'm following your detailed instructions, but I'm obviously not.

With your kind indulgence ... to be continued.

Let me come at this issue from a different direction, David. If I can get the guy who installed my new hard drive to retrieve the entire "Thunderbird" folder from the old hard drive ... the folder that resides in "C://Users/AppData ... and if I reinstalled Thunderbird on the new drive, then deleted the Thunderbird folder it installed and replaced it with the old one ... would that work?

Yes, but you don't even have to reinstall Thunderbird. The whole issue is caused by merely not having included the profiles.ini file in the backup. Had you restored that file together with the Profiles folder you have, everything would have been just like it was before. The whole issue is caused by Thunderbird having lost track of the profiles you had as a result of having created that file anew.

OK. Let me see if the guy can retrieve the folder. More later! Thanks so much.