Open Thunderbird, go to menu Help > Troubleshooting information > Profile folder < Open Folder ...., then quit Thunderbird. You'll see the profile folder located in a "Profiles" parent folder. Open "Profiles" and make a screenshot of its contents. At the same hierarchy level as "Profiles" you'll see a file profiles.ini Open it in a text editor and show us its contents.

Q: did you create backup copies of your Thunderbird profile folder in the past?

I don't see profiles.ini

See attached file of a screenshot

I don't see profiles.ini

You can't see profiles.ini since this file is not located in the profile folder itself. Open the folder Thunderbird and you'll see the file profiles.ini as well as the folder "Profiles". Please post screen shots of the contents of both, profiles.ini and Profiles

Go up two levels. You are looking at

"C:\Users\freig\AppData\Roaming\Thunderbird\Profiles\4vp9ztlm.New Default"

You will find profiles.ini in "C:\Users\freig\AppData\Roaming\Thunderbird

It should look something like the attached image...

See attached

See attached

Thank you. Please read my replies carefully: I am still waiting for the screen shot with the contents of the folder "Profiles" which is located in the Thunderbird folder. Otherwise I won't be able to compare the profiles in "Profiles" folder and in the profiles.ini file ...

Attached 3 screenshots. I had to take 2 screenshots for one of the the profiles folders to capture all of the files inside. The other profile folder was empty.

I don't know if I sent this or not.

Attached 3 screenshots.

No, you still didn't get it. Once again, and now please have a look at the attached screen shot in which I marked the file folder Profiles with a red rectangle: in ....\AppData\Roaming\Thunderbird\ there is a file folder named Profiles which should contain several profile folders. Please open this folder Profiles and take a screen shot of its contents. Take all the time you need since it's in the middle of the night in Europe and I will be back tomorrow...

Is the attached what you requested? Thank you for your assistance today and I look forward to your response tomorrow.

Is the attached what you requested?

Yes, it shows what I needed to understand your Thunderbird installation and to identify the profile you've been using until recently. Your profile folder is 4vp9ztlm.New Default and it is stored in the default location "Profiles" in \AppData\Thunderbird\ In the profiles.ini file I see the lines

[Profile2] Name=New Default IsRelative=1 Path=Profiles/4vp9ztlm.New Default

which correspond exactly to the profile folder 4vp9ztlm.New Default. So I wonder why Thunderbird on startup cannot find the New Default profile and shows the "profile missing" error message.

There is another line in the profiles.ini file StartWithLastProfile=0 The 0 (zero) indicates that on startup Thunderbird first opens the Profile Manager window, offering the user a choice between several profiles. • So what happens when you start Thunderbird? Do you see the profile manager window (image)? • And what happens when you select New Default and the click "Start Thunderbird"?

There is an anomaly in your New Default profile which strikes me: the oldest modification dates of its files are from January 2, 2006. It is as if you had created this profile one week ago! So your answers to my two questions above are of utmost importance. Can you post a screen shot of the Thunderbird main window when you start the New Default profile?

And what about the x4n0g1to.default profile on your Desktop? Is it a backup copy of an old (or maybe recent?) Thunderbird profile?

I have attached a screenshot of what comes up when I start Thunderbird. I intentionally unclicked the box which chooses a profile on startup until I resolve this issue. The New Default user is the only profile that works. What I mean by "works" is that the other 2 profiles give me the message, "Your Thunderbird profile cannot be loaded. It may be missing or inaccessible." Since I am missing all data from the decades of using Thunderbird I am hoping that I didn't lose everything when I reinstalled Thunderbird last week.

The New Default user is the only profile that works. What I mean by "works" is that the other 2 profiles give me the message, "Your Thunderbird profile cannot be loaded. It may be missing or inaccessible."

The "Thunderbird profile cannot be loaded" message is normal since if you have a look in the folder Profiles you'll see that it doesn't contain neither a "Default User" nor a "default" profile. So TB cannot open a profile folder which is absent in Profiles in spite of what is written in the profiles.ini file. And this is what I don't understand: have there been a "Default User" or a "default" profile in Profiles before and where are they now?

Since I am missing all data from the decades of using Thunderbird I am hoping that I didn't lose everything when I reinstalled Thunderbird last week.

That's what I would like to know, too. What happened that you had to "uninstall and reinstall" TB? Did you also delete the old profile folder or even the entire Thunderbird folder? And where did you get your TB data from when you reinstalled TB? All this is rather mysterious and I cannot follow the history of your doings since I lack information.

I already asked you "what about the x4n0g1to.default profile on your Desktop? Is it a backup copy of an old (or maybe recent?) Thunderbird profile?" Is this your old profile when you uninstalled TB? What does it contain since you think there are still messages missing data from decades?

When you ask above about the "x4n0g1to.default" profile on my Desktop, is it the same as "C:\Users\freig\AppData\Roaming\Thunderbird\Profiles\4vp9ztlm.New Default" in the attached screenshot? I believe this is the new profile created when I reinstalled TB. The old profile might have been deleted in my efforts to get TB to work. The reason I reinstalled TB was because it would not open. Everytime I tried to start the program I got the message "Your Thunderbird profile cannot be loaded. It may be missing or inaccessible."

Is there a way to locate a previous profile, even after it may have been deleted?

Is there a way to locate a previous profile, even after it may have been deleted?

Did you have a look in your Windows trash bin? I am a Mac user and I regularly make incremental backups of my "User" folder with Time Machine plus daily automatic backups of my Thunderbird folder in Dropbox, so even when fooling around with Thunderbird experiments I'm on the safe side. Windows users in this forum might give you advise how to restore deleted user data.