Let us start with the most basic part, (U)EFI. You can find it on every newer mainboard. For our successful setup you need to set it to "Legacy" or "Legacy+UEFI" mode in your BIOS. Please refer to your mainboard manual on how to accomplish that. It is important to do that, so that the installer will install the classic GRUB2 instead of GRUB-EFI. See Partitioner #1 "reserved BIOS boot area part.