I thought I would update this post as I was able to add the Realtek drivers for my NIC adapter into the ISO and I have managed to install ESXi 6.7 U2 on my MSi motherboard with AMD Ryzen 7 1700 processor.
However, I now receive a Hardware Virtualization Warning, indicating hardware virtualization is not a feature of the CPU or is not enabled in the BIOS.
I have confirmed hardware virtualization is supported and enabled in BIOS.
Any help would be appreciated,
Brian