The system setup shows Primary Hard Drive is none. How can it automatically be detected?

If your system is not detecting your drive it sounds like it has failed on you.
Time to get a new one.

Has the computer been moved recently?

Any changes to hardware recently?

Just started happening out of nowhere?

In system setup (I assume you are in BIOS) you can reset BIOS defaults to see if any change

You can try to replace the ribbon cable from the hard drive to the mother board

Other than above, as mentioned, drive probably may have seen it's last days.