Did you already mount the hard drive in an enclosure that can connect and access that drive via USB ?

Location used for the main profile that keeps your personal data (Root Directory on about:profiles).

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. Note that best is to avoid copying a full profile folder.

• bookmarks and history: places.sqlite
• favicons: favicons.sqlite
• bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
• cookies.sqlite for the Cookies
• formhistory.sqlite for saved autocomplete Form Data
• logins.json (encrypted logins;32+) and key4.db (decryption key;58+) for Passwords saved in the Password Manager
  key3.db support ended in 73+; to use key3.db in 58-72, make sure to remove key4.db
• cert9.db (58+) for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words added to the spell checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
• sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)

The files in the bookmarkbackups folder have their creation dates coded into their names, along with the number of items in the file (items include bookmarks, folders, and separators, in case the number seems high).

If you decide you want to restore one of these to your currently live Firefox profile, see the following article for steps: Restore bookmarks from backup or move them to another computer. That completely replaces whatever you have at the moment.