Audio Output is not appearing

[AmiraY]

HP Z2 Tower G9 Workstation Desktop PC

1. The speaker icon is the bottom taskbar appears "x" in red icon
2. Realtek (R) Audio is not appearing in Sound Settings
3. In Sound > Output > Choose your output devices status "No output devices found"
4. In Device Manager > Sound, video and game controllers only NVIDIA High Definition Audio is available
5. Device status shows the following error
   "Currently, this hardware device is not connected to the computer (Code 45) 
   To fix the problem, reconnect this hardware device to the computer."
6. We replaced with another unit of speaker, but still the same.
7. We tried uninstalled NVIDIA High Definition Audio, restart the PC and scan for hardware changes in Device Manager, to see if its detect the Realtek driver automatically, but it's not.
8. Last step, we installed and run a Realtek (R) Audio Driver to the PC but the Realtek driver still not appearing and no changes on the items reported above. 
    
   Kindly advise.

[TheOldMan]

Several of the outputs in the screenshots list "no output devices found"- as you indicated.  That would seem there are no speakers connected, so I need to ask - are there any speakers connected?  If yes, then where are they connected, which audio port?  That PC does not have internal speakers.

[AmiraY]

There is speaker connected. The connections are as following:

1. Audio cable connect to Audio line-out port of CPU to KVM transmitter
2. Audio cable from speaker connected to KVM receiver

[TheOldMan]

That is interesting.  IDK if that setup is causing the problem or not.  You might want to try a conventional setup, first.  That way, with a self-powered speaker connection, perhaps the computer can see a connection.  IDK how the KVM device presents itself to a audio output but the output level is not intended to drive a non-powered speaker.