ryley2637 said

I have a computer that had Windows completely re-installed and they didn't make a backup of the Firefox bookmarks before wiping the HDD. They had no backup .html files; had FireFox Sync set up or anything else that would normally backup the bookmarks. I thought about trying to use file recovery software to see if I can locate any of the old profile files that might still be on the HDD. Would this have a chance of being successful, and if so what files/folders should I look for that would have the bookmarks?

If they wiped the HDD, then even file recovery won't do any good to retrieving your bookmarks.

Best regards, Austin

Firefox creates only compressed .jsonlz4 backups and being compressed they only contain unknown binary data, so it won't be possible to do a low level search for this data in the case these clusters haven't been reused. A normal reformat wouldn't initialize all bytes to a know value as this would take a very long time to complete with current hard drive sizes, but merely re-initializes the file system data structure.