My suggestion is to not use the import feature, since you are experiencing difficulties. Instead, here is my suggesition: - ideally, set both PCs to have same TB version. Not mandatory, but ideal - be sure TB is not running on old PC for the copy - copy c:\users\<yourid>\appdata\roaming\thunderbird to a USB stick - install TB on new computer if not already done. - Be sure Thunderbird is NOT running on new computer during the copy - copy the USB thunderbird folder to c:\users\<yourid>\appdata\roaming. That will overlay the default profile that was created, so you will be prompted for overwrites. Allow that. - start thunderbird and the profile should be active.

Thank you David for your advice. I'm almost certain that when I asked this same question a couple months ago, you replied with the same advice. I wrote your advice onto a sheet of paper, did exactly what you outlined and it did not work. I got an error code, got disgusted & continued to receive my e-mails on this WIN 7 PC. However, in fairness to you, and with renewed hope, I will give it another try. By the way, BOTH PCs have the latest releases of both T-BIRD and FIREFOX installed.

And, to make matters worse, since I use Gmail as my e-mail client, I can't even access my e-mail accounts from the Gmail native screens through FIREFOX. Despite entering the EXACT same passwords into their box, I get error messages, alerting me that it's an incorrect password. This CANNOT be, and I have NO recourse to get a solution through Gmail. The irony is that I CAN open my e-mail accounts with NO problem using their native screen on THIS WIN 7 PC. So, the problem seems to be some 'secret' file in the WIN 10 PC that is NOT properly set. Again, THANK YOU! k.t.

Ok. An error code would most likely be a Windows error, since Windows File Explorer is the intended tool. If you do get errors, please post it. Thanks.

David,

 First, THANK YOU for the latest suggestion to move my existing files to the Win 10 PC.  Succinctly states, it failed once again.  I followed your instructions; was able to copy the ...\Thunderbird folder from the 7 PC to an 8GB drive.  When I got to the 10 PC, I could not find the folder tree .... doing a Explorer search I found it. I copied the thumb drive to the ...\Thunderbird folder. It is about 5.5GB ... did it in less than 10 mins.  Then, I opened Thunderbird on the 10.  The first screen that appeared was the Google 'Gmail' screen, showing my main e-mail address.  When I typed in my password, I kept getting an error message.  Certainly I know my password.  Also, since I have 4 different e-mail identities, on the Win 7 PC, they all appear on the left column of Thunderbird.  On the 10 PC, only my main e-mail identity appears.  So, it's obvious that the copying of the files has not completed properly, and now I still can't gain access to my e-mails on the 10 PC, since Google/Gmail is interfering with this connection.

+++++++++++++++++++++++++ Also, since I'm still using the Win 7 PC, when I attempted to open this THUNDERBIRD help session, I clicked on the directive, "This does not solve my problem", to which it opened FIREFOX. When FIREFOX fully loaded, it started to open this MOZILLA Support page, but then I got the (very frequent error message, "GAH!, Your Tab just crashed". I pressed the restore button and the error message reappeared at least 4 times. So, in desperation, I chose the other option, close. Then went back to the original page, "This does not solve my problem", clicked on this sentence and FIREFOX reloaded, and now I was able to enter this reply and additional comments. ++++++++++++++++++++++++++++

 Finally, it seems that the folder where Thunderbird is residing is in a hidden folder tree.  On my version of Win 10, there doesn't seem to be any direct access to the c:\users\<ownerid>\appdata\roaming\ .....  I had to type in this chain into the Explorer window to access it.  So, this was a frustration in itself .... I know it's NOT your problem, but I just wanted to mention it.
 The inner workings of WINDOWS is a BIG enigma to me, and has been since 1984, when it was first released!!!!  At this point, I don't know how to solve this file transfer problem, since other local technical people that I've talked to about this situation have told me that they can't help, and have suggested that using Thunderbird is NOT a wise choice, which bothers me since according to other sources, Thunderbird IS THE MOST POPULAR e-mail software in circulation.  So, this must be some personal negative bias, but it still doesn't solve my problems.

THANK YOU. k.t. P.S. I'm located in a suburb of Tampa, FL.

Thunderbird follows Microsoft recommendation to keep data areas separate from executables and the appdata folder is the norm. To make the folders visible, start windows file explorer, click View>show>hidden items. Then follow steps I explained earlier. I respect that some people do not like Thunderbird, but I see that as a personal preference. Thunderbird works.

YES, David, I understand. I've been using T-BIRD ever since I switched from WIN XP with its OUTLOOK EXPRESS e-mail software. I personally have NO negative attitudes. I just was parroting what some others have said.

However, I still have the problem of NOT being able to access the e-mails on the 10 PC, or T-BIRD showing all 4 of my e-mail identities. So, there's still a problem.

 How do I get over the hurdle with the password problem with Gmail, since

this seems to be the brick wall, stopping full access. The irony of it all is that when I opened T-BIRD this morning after transferring the files from the 7, T-BIRD downloaded 20 latest e-mails for the main identity. However, I cannot send or reply to an existing e-mail since Google/Gmail is blocking this attempt. This remains my fundamental problem, and I know I have no recourse to Gmail for technical assistance.

Your problem seems to move from one issue to another. My suggestion is to mark this solved and open a new post on the Gmail issue. My inference is that the win 7 pc is using the OAUTH2 password. You are attempting to use the 'real' password online, which may have changed. If you have a backup email account, you can reset your password via that route.

OK!, I got your latest message about OATH ..... I don't understand any of this, so I think this problem is far beyond our ability to solve it by these communications. Your advice to close it, it probably best now. There is a BEST BUY store in the mall across from my subdivision, and they have a GEEK SQUAD unit in the store. Maybe at this point since I cannot get any assistance elsewhere, this is my last option. (NO deference to you personally!!!!!)

I can tell you that I significantly less problems programming ASSEMBLER and/or FORTRAN IV on an I-B-M mainframe w/ stacks & stacks of Hollerith cards back in the '70s & '80s than I do now with WINDOWS.  But, this is NOT your problem.

Again, THANK YOU for all your assistance .... I DO appreciate it very much. One final note .... Please mention the ongoing problem that I experience very frequently with FIREFOX, getting the 'GAH!, your Tab crashed' error message. This is also a very frequent occurrence. FIREFOX is set for automatic updates, so I know I'm running the latest release. I can tell you that this WIN 7 PC dates back to release 5x.xxx, and I NEVER got this message, OR the very frequent '(Not Responding)' error message like I do now, and nothing has changed over these past years. The C:\ is barely 1/4 filled. THANK YOU!!!! Good bye. k.t.