I am setting up Thunderbird on a new Win10 PC. I installed v78.14.0 but have not yet done any setup configuration. The installation created two profiles in the standard default profiles location at C:\Users\MyUsername\AppData\Roaming\Thunderbird\Profiles, e.g.: otbmcskq.default pgsvtwmc.default-release I currently use a Win7 PC with Thunderbird v52.9.1 (updated through the years from v2.0.0.24). I want to migrate the address book, mail, and local folders from this old PC into the corresponding folders in the fresh profile on Win10. I also want to move (copy, paste) the fresh profile on the Win10 PC out of the standard default location to a folder on a separate hard drive on that same PC: D:\Data\Thunderbird 1) Which of the two profiles shown above should I move, the default profile or the default-release profile? 2) Or should I just create a new profile that points to the folder on the D: drive? 3) If I create a new profile that points to the folder on the D: drive can I then remove the two profiles shown above (after testing, of course)? 4) My plan is once I have a profile at the new location on the D: drive I will go through and configure the account settings and all the other settings before copying over the address book, mail, and local folders from the old PC. Does this sound like a reasonable approach? Thanks!