Missing hard drive

Win 8.1 64 bit.
The C drive is not the problem, its my back up drive (E drive).
It does not show in "This PC" or Disk Mgmt.
Though the BIOS sees the drive.

I tried swapping the with another drive I have laying around - nothing.
Tried a different sata port on the mother brd - nothing
Went to the ASUS website - I have the latest BIOS firmware and found no other utilities that seem helpful OR new.
Tried CMD, then list disk - also nothing.
Tried mcaffe rootkit remover - clean.
Anti -sypareware (the one with bug icon) - clean
Norton A/V also clean.

What else should I try?

 

Update -
Mistook recognition of my DVD drive for the Hitachi HHD.

I ran Windows Troubleshooting 'program' it found the HHD. I opened This PC and there it was, then quickly disappeared.

So now seems neither the mobo or the PC sees the HHD.

I did connect a SATA-USB Adapter and have access to that drive. So drive itself seems OK.

I now wonder if when I went from Win 7 to 8 that something messed up.

 

Resolved.
Tried the 'ole remove & re-insert -
I unplugged then reconnected the cables that go from the drive to mobo & re-booted.
Success! really have no idea why that works- its not like the Tower is constantly in motion and things just happen to go loose.