Bookmarks are stored locally in your Firefox Profile usually in C: which is seperate from the folder where you actually install the browser. So each time you reinstall that data is brought back. Since you don't have the HDD anymore you do not have that folder right now. :)

You can always use Firefox Sync so that your bookmarks get synced across devices in similar cases.

Check with a tech about recovering data from the old drive.

Rugwed, yeah, that means my bookmarks died with the old hard drive. Next question.... I've never been able to get sync to work. My mobile phone has most of my bookmarks installed, but I can't get them onto Firefox on the laptop. Any ideas?

Note: I prefer to use an older version of Firefox (47). Could that be a problem? It won't even create NEW bookmarks :/

Yes that could be it. You need to have the newer Sync across all devices for it to work. In 2015 the Sync feature moved to a model where you sign in with a Firefox account on your browsers for the sync to work. You should upgrade to a recent version of Firefox without uninstalling the existing v47. That way you will retain the current bookmarks. Then when you are updated you can sign in with a Firefox account just like you did on your mobile phone and it will sync right across.

If you need an older but not ancient version of Firefox, maybe the Extended Support Release of Firefox 52?

https://www.mozilla.org/firefox/organizations/faq/

In the end, I bit the bullet and upgraded to the latest Firefox, which then synced all bookmarks from my phone. Thanks all.