Windows is hiding the appdata folder, along with a large proportion of the files on your system. Windows search does not search these hidden folder either.

If you open a windows run dialog (Windows key + R) and type %appdata% windows will show you the hidden appdata folder and it's contents, just as Thunderbird shows you the hidden profile folder. Or you can turn on the viewing of all files and folders in Windows. See https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files for Microsoft's instruction to set that up.

Thanks, Matt, for the pointer on showing hidden files. I found the Profiles folder, but am encountering other problems. For one, showing hidden files shows a Google Picasa folder, named .picasaoriginals, on my desktop, with photos in it. I don't want it hanging out there in view, cluttering up the desktop, but am afraid to delete it as I think it may delete the photos. I have no idea why it is there.

I tried to work around this by creating a shortcut to the Profiles folder, intending to turn off the show hidden files feature and find the Profiles folder via the shortcut, placed in my Start Menu. When I created the shortcut, Windows 7 named it "Profiles - Shortcut." But when I click on the shortcut, it links to the 1pp6ndy5.default folder, which is the folder inside the Profiles folder, and I cannot use Windows Explorer to tree back one level to the Profiles folder. Mozilla says I should copy the Profiles folder, not the 1pp6ndy5.default folder.

I used to back up Thunderbird daily using MozBackup, which was simple, but it is no longer supported, and is reported to have glitches that may cause backed up profiles to not restore. Is there a way to get a shortcut to the Profiles folder to actually link to the Profiles folder? Or safely eliminate the Picassa folder from ghosting on my desktop?

My personal view, and it is my own is use a batch file to do the backup. REgardless of what is "normally rcommended" I suggest you include the top Thunderbird folder as it contains the profiles.ini file. This is the file that tells Thunderbird where your profile is stored. You must also have all of the account directories in account settings in their default locations. Directories not in the Appdata\Thunderbird structure will not be included in any backup you create.

in notepad paste the following text

copy %appdata%\Thunderbird\*.* /S BackupLocation

Where BackupLocation is the place you want your backup. Say E:\

Save the file and when saving change the file type to all files then add a .bat extension to the file. something like backupThunderbird.bat

An alternative is the import/export tools which has a profile backup routine built in which can schedule a profile backup. https://addons.mozilla.org/en-US/thunderbird/addon/importexporttools/

Thanks for the suggestions, Matt. I do not understand your instructions on using a batch file. I found a different solution that I think will work. I discovered that creating a shortcut to a folder does not link to that folder in its closed form, but in its open form, with its contents displayed. This is why when I created a shortcut to the Profiles folder, it went to the 1pp6ndy5.default folder inside it, and I could not tree back to Profiles. So I created a shortcut to the Thunderbird folder, which shows the Profiles folder inside it. From there it is easy to copy and paste Profiles to my external hard drive for back up. With the shortcut in now place, I turned off "show hidden files."