Be sure that TB is not running when you copy roaming\thunderbird folder. That's critical. Then install tb but do not run. The copy to the roaming\thunderbird on new PC and it should start immediately. When it prompts to create an account, it means something is missing from the copy.

Thanks David. Unfortunately that didn't work. Here are the exact steps I took: New Windows Install 1 - Close Thunderbird and verify closed through Task Manager 2 - Uninstall Thunderbird through Settings 3 - Zipped current copies of local and roaming just in case 4 - Deleted local/thunderbird, roaming/thunderbird and program files/Mozilla Thunderbird

Old Windows Install 5 - Verify that Thunderbird did not open on startup through Task Manager 6 - Saved local/thunderbird and roaming/thunderbird to a shared drive

Back to New install 7 - Install Thunderbird selecting NOT to launch Thunderbird at the end 8 - Copied local/thunderbird and roaming/thunderbird from shared drive 9 - Start Thunderbird

Failed. It asks me to enter email info. After entering the first one, there are still no filters, nothing in local folders and the second email address is not configured.

Did I miss something? I know that the instructions do not mention local/thunderbird but even leaving that part out of it changes nothing.

Those entries are likely missing because TB is setting up a new profile alongside the other one. Can you create a screen shot of the roaming\thunderbird\profiles\yourprofilename? And one of your imapmail folder if you have imap accounts and one of your mail folder if you have pop accounts. TB thinks something is missing for your profile to be complete, and it seems it believes there is no email account.

Thanks again David. I'll do this later today when I get back home. There are no POP3 accounts, only imap and local folders. I'm assuming you want to see a file listing so I'll get that from both installations (working and new as copied over).

After doing a file compare between the 3 files (I did a third of the new install after starting TB), I noticed that there were some files added in the "after" structure. Which then made me check the versions again. The versions were the same (91.7.0), but the old install was running 32 bit and the new was running 64 bit which downloaded by default. So after doing some searching and finally being able to find 91.7.0 32 bit on a 3rd party site, I installed that on the new Windows install, copied over the user AppData again, fired up TB and everything works.

So yeah, the problem was 32bit vs. 64bit. Thanks for leading me down the right path to finding the problem.

I'm pleased everything worked out ok. Thanks for sharing that.

It is not the 32 V 64 bit that is the issue, it is the install directory. Windows using program files(86) for 32v bit and program files for 64bit.

This is not all that important but the day to day things, but for the profile per install that Thunderbird inherited from the Mozilla core, it uses the install directory as part of working out if the version is different. Thus forcing a new profile folder be used.

There are two ways around this.

• Copy your old profile data into the profile Thunderbird has now created and start Thunderbird. everything should be fine.

• Start Thunderbird with the command line. (Windows key + R and type the following into the dialog before clicking to run.

Thunderbird -p -allow-downgrade 

Generally if you are using MAPI to scan and send mail or running accounting software that uses MAPI the bitness of the install is important as MAPI does not appear to function when say the accounting is 32bit and Thunderbird is 64bit. The bitness must match is what I think is happening (I am yet to find someone that actually understands MAPI, despite so many p[rograms using it.)