MacOS High Sierra is here today, I downloaded and installed on my external USB drive. It works beautifully with my HP x360 Haswell HD4400 i7-4510u which having problems with the last MacOS Sierra 10.12.6. This tutorial can be used for all Mac OS X and various PCs and Laptops. Before we upgrade to MacOS High Sierra, we should know which Apps are not compatible: VMWare 7.x
On my El Capitan, I could only download 19MB short version of the High Sierra 10.13, I had to use to download and it also create the USB Flash installer for me. The only thing I need is the Kernels folder that need to be extracted from Core.pkg using Pacifist.