Do you have your old hard drive attached as, say, the E drive?

First step, set Windows to show hidden files and folders. Microsoft has the steps here:

https://support.microsoft.com/en-us/windows/show-hidden-files-0320fe58-0117-fd59-6851-9b7f9840fdb2

Next, click through on the old drive:

E:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles

Here you will find one or more folders, depending on how many different Firefox profiles you accumulated over the years using the old hard drive. Each folder will have a pair of files used to store logins:

• logins.json
• key4.db

If you find more than one pair, choose the ones in the most recently updated folder.

Those files need to be transferred to your new (currently live) profile together as a set.

Let's pause -- are you able to track down the old data?

Thank you SO MUCH! I had followed several like advise postings, but they all mention the "local" user folder.

I "usta-was" computer savvy (Ran & owned the People's Re-pubic of Kalifornia Central Coast's largest sales & service - "Mount Desert West" in Lompoc) but closed in 2008. In those last 13 years I have forgotten more than most ever knew! now, me included! LOL) Amazing what being 75 does "for" you. I am still hunting for the guy who called these "The Golden Years" I REALLY want to "talk" to him! Thanks again, I need one more frustration like a bullet between the eyes.

I'm glad you had all the other pieces of the puzzle already; it's a lot to write out.

It's interesting to think about those early years, when we had in-person user group meetings where people brought computers built from parts. Now some people will only be aware of sealed slabs with GUIs. They missed so much.