When you did the upgrade, did Windows ask what you wanted to do with your data? Options include leaving it in place or creating a backup. The backup folder would be called:

C:\Windows.old\

If you have that folder and it appear to have fresh data:

Turn on viewing of hidden files and folders: http://windows.microsoft.com/en-us/windows/show-hidden-files

Then look for

C:\Windows.old\Users\your-user-name\AppData\Roaming\Thunderbird\Profiles

Assuming you find your old profile folder there, you can copy it to the normal location. Don't just point the profile manager into C:\Windows.old because it normally will be deleted after 30 days.

jscher2000 said

When you did the upgrade, did Windows ask what you wanted to do with your data? Options include leaving it in place or creating a backup. The backup folder would be called: C:\Windows.old\ If you have that folder and it appear to have fresh data: Turn on viewing of hidden files and folders: http://windows.microsoft.com/en-us/windows/show-hidden-files Then look for C:\Windows.old\Users\your-user-name\AppData\Roaming\Thunderbird\Profiles Assuming you find your old profile folder there, you can copy it to the normal location. Don't just point the profile manager into C:\Windows.old because it normally will be deleted after 30 days.

I took the option "to leave in place". I have the profile; the problem is that Thunderbird ignores it. I have tried creating a new profile and then copying the contents of the old profile into it: that does not work. There is something strange in the profile that causes Thunderbird to reject it. I have tried a couple of backup copies of the profile and none of them work either.

Please post images showing what is going on.

In Thunderbird Help > TRoublshooting Information click on 'Show folder' button. Post image of this window. so we can see which profile is currently used by TB.

click on 'Profiles' folder it should list all profiles created. post image of window tell us which profile you copied over.

Did you copy paste the backup 'xxxxxxxx.default' profile folder from the windows.old into the 'Profiles' folder ? (x's are letters and numbers) OR did you copy paste the entire 'Contents' of the profile name folder into the new default profile created by Thunderbird when you reinstalled Thunderbird and ran it for the first time ?

open 'profiles.ini' file using Notepad post image showing contents of this window.

I have solved the mystery. Apparently something in the upgrade process did the nasty to some part(s) of the profile, which is why when I removed some of the profile entries (actually, overwrote with corresponding newly created ones) everything worked. Fortunately I had backups from before the the 3 day upgrade extravaganza and restored that profile and all is well. I don't think I have lost anything since I kept out of Thunderbird (and everything else) while upgrading. Just to be on the safe side, I also restored the mailbox folders. So far so good, Thanks to jscher2000 and Toad-Hall for their assistance.