See [[recovering important data from an old profile]] in particular the section "Copying files between profile folders" and the one below it that describes the files in the profile folder. The article shows how to find your current profile folder, you will need to find the equivalent folder on the old drive, the path to the current profile folder should show you where to look on the old HD for the old profile folder. The actual folder name for the profile folder will be different, but the path to it should be the same.

See also http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox