Over the past weekend I was working on a whitebox ESXi host and wanted to upgrade it to ESXi 5.5 Update 2 from an older version of ESXi 5.1 using a realtek R8168 network card. While I could have performed an in place upgrade, such as via command line, a clean install was preferred. However, VMware has removed a number of NIC drivers from ESXi 5.x and trying to install with the base ESXi image would result in a “No Network Adapters” error during install.
In order to do a clean install you have to re-add the Realtek R8168 NIC drivers back into the ESXi 5.5 image, otherwise a NIC will not be found and thus ESXi will not install. These are the steps to easily re-add the Realtek R8168 drivers into ESXi 5.5 ISO by making a custom ESXi 5.5 image.