What method can I use to correct a socket permissions error when obtaining IPs via DHCP?

I have an HP Pavilion 15 laptop (TPN-Q130) on which I recently did an in-place upgrade from Windows 10 Build 1909 to Build 21H1. Ever since the upgrade, my network adapters (both WiFi and Ethernet) are unable to obtain IPs via DHCP. When using ipconfig /renew from the command line, I get the error: "an attempt was made to access a socket in a way forbidden by its access permissions".

I tried using static IP assignments instead, but to no avail.

When I attempt some basic troubleshooting (e.g. PING 127.0.0.1) I get a General Failure error. This would normally indicate to me that the TCP/IP stack is damaged somehow. I have tried resetting using various NETSH commands.  I've tried disabling miniport drivers. I was going to revert back to the previous Windows build, but when I tried that, I received a message indicating that the "files needed to restore your previous version have been removed".  Aaaarghh!!!!

So, I ran the in-place upgrade process again in the hope that it would replace any damaged or missing networking components. No good. 

Has anyone encountered this before? Is there a fix that doesn't involve factory resetting the PC? There are numerous files, programs, and settings on it that I really don't want to lose.

Any help would be appreciated.

Thanks.  :-)