Customising VMware ESXi ISO - Adding Legacy Network Adapters

Part of my objective to understand VMware better is upgrading my lab hosts to a current version of ESXi, I've chosen 6.5 because it's the latest version and my lab is a long way away from a production environment so I don't have to worry about using a proven and stable release.

The snag I have is that one of my servers is a "white box" microserver, a Shuttle DS81, a great little box designed for digital signage, but the built-in Network Card is a Realtek 8111G, which is unsupported by VMware. This stops ESXi 6.x onwards being installed on the device. Error message shown below:

The way round this is customising your ESXi ISO image before installing it, adding the necessary drivers. Now this isn't a hack perse, because VMware actually gives you a tool in vCenter to do this, called the Image Builder, however I suspect this would affect your support from VMware because you are using unsupported hardware. I'm not fussed because this is a lab to enhance my learning, plus it's a great little box, very low power, reasonable spec (4 CPU, 16GB RAM), so there's no way I'm not using it.
VMware Image Builder:
https://blogs.vmware.com/vsphere/2016/11/getting-started-new-image-builder-gui-vsphere-6-5.html

Now I didn't actually use the image builder to customise the ISO files, I did give it a quick go but it is not immediately intuative for a complete novice.

There are 2 other ways (that I have found) to customise the ESXi ISO:

• ESXi-Customiser
• ESXi-Customiser-PS

The ESXi-Customiser is what I used, it's not an official VMware product, and has actually been suceeded by the ESXi-Customiser-PS but I found it so simple and easy to use, and works perfectly for ESXi 5.5, 6.0 and 6.5:

https://www.v-front.de/p/esxi-customizer.html

Just one note, I couldn't get this to work on windows 10, I had to use a win7 machine.

The ESXi-Customiser-PS (power shell), actually looks like it's semi easy to use as well but I'm a novice and my version of windows 10 said it couldn't run powershell scripts, so instead of getting side tracked learning about windows power shell (I'm concentrating on VMware, one thing at a time!), I decided to try the easy way, a 3 click, the ESXi-Customiser (above).

For anyone having the same issues with the Realtek 8111G NIC, the drivers I used were the 8168 driver pack, this page shows you how and provides a mirror:

http://www.computertechblog.com/adding-realtek-r8168-driver-to-an-esxi-6-0-iso/