Assuming you use windows: - exit thunderbird - copy c:\users\<yourid>\appdata\roaming\thunderbird to external media - install thunderbird on new computer and then EXIT (very important) - now, copy the backed-up thunderbird folder to c:\users\<yourid>\appdata\roaming to overwrite to existing thunderbird folder. - restart thunderbird

Thanks for your quick reply. Due to my ignorance about computers, I don't understand steps 2 ("copy c . . . media") and 4 ("now . . . folder"), and only guessing that I may be able to manage 3. Could you be so kind as to explain these steps in more detali, e.g., What am I to copy in Step2 and where do I find users and appdata?

- click windows icon on task bar - click the 'File Explorer' icon - click the View option on menu bar - click the show>hidden items options - now, in left column, look for folder named 'Users' - within that folder will be one that has your name or part of your name, click that - now, it will show a number of folders, one of which is appdata. click that - now, there will be a couple of options. click 'roaming - now, there is a list of folders. Highlight the one named Thunderbird, right-click and COPY to external media

You will do similarly on new computer.

Thank you for your reply. My old computer is on the verge of collapse so I am a bit late to reply.

You wrote

- install thunderbird on new computer and then EXIT (very important) - now, copy the backed-up thunderbird folder to c:\users\<yourid>\appdata\roaming to overwrite to existing thunderbird folder. - restart thunderbird

How do I install Thunderbird on the new computer from the usb? How do I do the second step? What is the backed-up folder? And how do I copy it to "c:\ users . . . roaming" and then "to overwrite to existing thunderbird folder"?

I am very, very sorry for my computer ignorance.

Ok, let's take a different approach. If your profile is less than 2 gigabytes, do this: - click Tools>export on old PC and save to USB stick - on new computer, click tools>import>import from another thunderbird installation and select the exported zip file on USB stick.

Or, you could use the standard approach. it's basically my original suggestion, but done differently. https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

First, my profile is nearly 3 GB. The site you recommended was well written--for Explorer. I have Edge, so the instructions do not correspond with Explorer. I am stymied after I click "show>hidden items": On the screen appears only one folder without any left column nor any other information. When I click on the folder, nothing happens. "Users" is nowhere to be found. What do I need to do?

By 'Explorer', the article is referring to 'Windows File Explorer', which is on your computer.Click the Windows icon in task bar and a menu will pop up and one of the choices is 'File Explorer.' The folder named 'Users' is in the root of drive c, and is not hidden.

I thought it was solved, but when I click on the Thunderbird icon folder on the usb, "copy" is no longer available. How can I copy the profile folder without it?

I found "Copy" again, in a sub, sub file. As I do not see any menu button on the screen (Step 4 in the article by your colleagues), I have gone to the Profile Folder which I am now able to open .No "Windows File Explorer" appears nor even the usual Windows task bar. What does appear is "Profiles" and under that "Kingston D[ my usb]>Thunderbird>Profiles," and nothing else over, on the sides, or under, except "Sort" and "View" which lead nowhere.

Have you considered taking the PC and the USB stick to a computer support person? I think that person could get this done for you rather quickly and ease the tension you're likely feeling. I do encourage you to develop some basic skills in File Explorer, as Thunderbird an other software regularly interact with them. Knowing how to copy files is an important skill to have, especially when moving to new computers or if your PC or Thunderbird crashes. That is my recommendation.

Yes, I could go to the store where I bought the new computer as it is nearby and the personel are too helpful; everything is done in the blink of an eye. I wanted to do this myself with help from Thunderbird so that I would be more versed in the technical procedures.

I thank you for your efforts. You have certainly tried to help.

As you recommeded, I did go for help.

The help I received may also benefit you, your colleagues, and subscribers. It follows: if someone, who confesses to be computer ignorant, asks for steps to resolve an issue, avoid assumptions, and provide all the steps as requested, overlooking none. The problem was that I did not know that Thunderbird first needed an installation place on the new computer to be installed. Obvious? For some, yes, but not for me.

I am grateful for all the help you gave me in installing Thunderbird on an usb.

re : The problem was that I did not know that Thunderbird first needed an installation place on the new computer to be installed.

Yes, I understand your situation, but most people know you cannot run programs that are not on your computer.

But it would be helpful if you could to help us to improve instructions for people like yourself, perhaps you can offer more info and tell us what precisely did you not understand about the following line. - install thunderbird on new computer and then EXIT (very important)

When I read that line ("install . . . important"), I assumed that the Thunderbird (TB) I had transferred to an USB unit would now install itself in the new computer as the unit had all the information. For those such as myself who need step by step instructions, I think the following sort of instruction could be of help with this issue:

You have now transferred Thunderbird and your TB information to the USB unit, but you will need to create a place for TB on your new computer to funnel and store that information. To create that place . . .

I hope this helps, everyone.