Try clicking on the "Settings" icon and checking the "Scan all files" box and see what happens.
I have now tried that two ways. The first was simply scan all files using the single name I was seeking.
I soon had a huge list of items and, very clearly, most of them would not be related to the name I sought. I'm guessing that the program brought up every file that contained the name within another word. For example: Seeking "for" would generate a list of every word like forget, forgive, Ford, et cetera.
That's not very helpful.
I then tried by putting in both the first and last names. That search generated another long list except that the name I sought absolutely would not be in even one of them.
Even less helpful, especially considering that the Spotlight search generated results in which every single item was pertinent.
