@Kevin_Z I may have stumbled on the solution and thank you for your time ahd efforts. It appears that the "main computer" didn't have (or was changed) of it's permissions in the register: (This has...

@Kevin_Z The "other computer - Windows 10 Pro 20H2" when it powers up first; connects and when I power up the "main desktop - Windows 10 Pro 21H2" it will also connect but not when the main starts...

@Kevin_Z Thanks Kevin for replying. This is only at start-up (power up). No games stuff or streaming boxes. I don't see how you can test the LAN connection to the router on the computer if there is...

At Startup: Lan card sees the internet signal and then it doesn't, router emits a long beep, no activity at Lan card. therefore no connection. Running: netsh int ip reset then netsh winsock reset...