The information I've seen indicates that the Thunderbird profile files for Windows machine resides in the users/appdata/roaming/thunderbird/profiles folder. However, and maybe I'm going crazy, but on a new computer I installed Thunderbird from the Windows store, and the resulting Thunderbird profiles information (upon installation) was seen to be located ONLY in the users/appdata/local folder, and there was NO Thunderbird folder in the users/appdata/roaming folder. This caused problems with using the instructions for moving email address-book information "abook" files. All of the support information I located directed one to ove the "abook" files to the profile folder located in the users/appdata/roaming/thunderbird path. Since there was no thunderbird folder located in that path, that's a problem. I uninstalled Thunderbird and re-installed using the application downloaded from the thunderbird.net website. Wella! Now there was a thunderbird folder in the "roaming" folder, and I was able to move the "abook" files from the old computer.