Where are these cache.trash folders? I don't have any on my computer.

The transfer process should be straightforward: copy the Thunderbird folder on the source computer, delete the existing Thunderbird folder on the target computer, replacing it with the Thunderbird folder from the source. All while TB is closed. The default location is: C:\Users\username\AppData\Roaming\Thunderbird

Sometimes, doing a direct copy seems to miss files; add the folder to a zip archive, then copy the zip and extract on the target.

Thank you

These folders are in thunderbird/profiles/4rvq****. default where * is a letter or number. As both the video and instructions say paste without deleting the existing profile I will try your way now. We are due visitors half an hour ago so this may take a while Note there are 236 items in that folder

Thank you sfhowes I tried your suggestion of deleting the Thunderbird folder first from the new drive and it did not fix the problem but it did produce an error message that may show what the problem is.

As I understand it the attached error is saying that the new Thunderbird cannot use the old profile because the new Thunderbird is on F drive and the profile is linked to C drive. Am I right?

I know you can link TB to a profile in a data disc but can that be done after TB has been in use for several years?

Obviously that would solve the problem as I could move the profile to one of my data discs (which are backed up daily) and that would solve the backup issues as well.

If so, and the process differs from a clean install, where can I find the information on this process.

Alternatively can I edit the profile to point to F instead of C until the new disc is stable or do I need to save the profile again and just overwrite windows on the C drive and start from scratch?

If the original copied profile was in the default location on the C drive, and you copied it to the default location on the new C drive, TB would have read the profile (except, see below). But if the profile was on another drive or non-default location, it could result in the error in your picture. Fortunately, you should be able to 'point' TB to the desired profile, no matter where it is, using Profile Manager. Close TB, Windowskey+R, type thunderbird.exe -p When the PM window appears, it may show a list of profiles, and if so, choose one and see if it launches. If it shows the same error, create a new profile in PM and browse to the location of the profile you've copied over.

http://kb.mozillazine.org/Moving_your_profile_folder_-_Thunderbird

A side note about copying the Thunderbird folder: I copied a TB folder from a 68.3.1 setup on one computer to ...Roaming on another computer, also with 68.3.1. Launching TB on the target PC produced an error message that is a result of the new 'profile per install' feature of TB 68. Closing the error window, I then launched PM and was presented with a list of the profiles I had on the source PC, and launched the original .default profile without any issues.

Thank you I eventually got it working after a lot of trouble shooting. Given the computer is dual boot the new operating system is on drive F: which means that TB should have been on F:\Program Files (x86)\Mozilla Thunderbird but it was on F:\Thunderbird. I deleted that install and the directory, created the F:\Program Files (x86)\Mozilla Thunderbird directory and reinstalled using custom install.

I then tried the normal delete/replace profile using both the webpage way and your Win-key +R way with no joy. After many tried using the webpage process to try and get Profile Manager to open I decided to try moving the profile. Following the webpage way of pasting Thunderbird -profilemanager to the run line in Windows Start menu opened TB. Likewise pasting Thunderbird -p also opened TB. Your Win-key Thunderbird -p however opened the Profile Manager and on the third try (third option provided) TB suddenly worked.

In summary - many thanks for the Win-key +R option as that was the key to success.

Yesterday I rebooted twice and TB worked

Today it is back to the initial screen asking to set up accounts and none of the above worked.

I am going to bite the bullet and format the old c drive and reload windows on C (and kill the dual boot copy on F)

I have saved the latest TB profile on two other drives using Synchredible which reports that both copies are 100% complete

I will update once I have finished and loaded all my browser, office, sound and graphics software etc and will load TB first seeing as it is the problem child.

I have been told over and over, Thunderbird does not happily use the same profiles folder for windows and Linux. There are just to many saved paths in the preferences and databases that in windows use an \ and in Linux use a /

As for profile manger stuff. Look at about:profiles in the troubleshooting information on the help menu. I talk about in it windows here https://thunderbirdtweaks.blogspot.com/2019/09/i-lost-my-profilemail-on-update-to.html

The about:profiles has a button to launch the new profile wizard which basically allows it's use to replace the original profile manager.

Well TB is now working perfectly. I have rebooted at least 12 times (and windows has rebooted multiple times also as part of the updates) and it opens correctly every time.

I am guessing that the problem was somehow related to the new operating system being on F: drive instead of C: drive and/or both of the dual boot options being Win7.

After I reinstalled Windows and its many updates over the top of the existing windows on C: and loaded all the motherboard software I loaded TB using sfhowes method of deleting the new TB profile and copying the old profile to roaming and it worked instantly. Since then I have loaded FF browser to replace IE and most of my other software with a reboot after each program install and TB works perfectly every time.

Thank you for you help - it kept me sane through all this