Hi gabbyfranco, could you try this:

First, set Windows to show hidden files and folders:

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

Next, I'm not sure how the files were arranged on your external backup drive, but here is where Firefox's files were originally:

C:\Users\username\AppData\Roaming\Mozilla\Firefox\Profiles\individual.profilefolders

Can you find a path similar to that on your external drive?

The folder you would hope to find is called bookmarkbackups and there would be one per profile folder. If you don't find the full path, search the drive for any folders named bookmarkbackups.

Anything?

The files in bookmarkbackups are compressed (the lz4 in the .jsonlz file extension indicates LZ4 compression). The file names should indicate the creation date and number of items.

To replace your current Firefox bookmarks (usually just a few default bookmarks in a new installation) with the contents of a backup file, use the Restore feature, and click "Choose File" to point Firefox to the backup file.

See: Restore bookmarks from backup or move them to another computer

Any luck?

Sorry but I will have to try this tomorrow. Thanks for your response but I got really busy with family affairs tonight. Thanks again.

You've been a great help. Thank you very much!