I'm not sure who "they" were, but did they make backups of any of your data before handing the computer back to you? Firefox stores bookmarks and other data under your Windows user profile folder. Depending on what was done with your system, that might have been preserved somewhere, or... the or is not good.

Did you ever set up a Firefox Account and the Sync service? Although Sync is not designed for use as a backup, sometimes you can use it to recover some previously saved data.

"they" was the IT department at my school. And no that was, of course, not done. And What they did do was reinstall my windows software since it had gotten corrupted in the update. If I did set up a Firefox account I can not remember any of my information. I know not very helpful for you, but I really appreciate the assistance!

I'm really sorry to hear they didn't take better care of your data. The probably also didn't do a secure disk overwrite, so if you want to run a long process of trolling for deleted files that might be recoverable, you could download this program:

http://www.piriform.com/recuva

The files you're looking for have names similar to

bookmarks-2017-12-02_2345_gibberish==.jsonlz4

(Where the date is listed and 2345 is the number of items in the file.)

Probably not. I appreciate the assistance and I will try this and fingers crossed will be able to find my bookmarks!