First of all, you have done a great work, so far.
Because especially for that its possible to install antergos from the newest Full-ISO via self-created usb-installstick (multisystem) on a HP Elitedesk 800 and EFI-support worked. that is about maybe 5 days left.
But now, after that i remove the Harddisk1 and changed it with a Win10 Installation Harddisk2 without Harddisk1(Antergos) and then i changed it back the Harddisk1 with my Antergos-Installation it was unable to start the Antergos but Win10 start at the same procedure.
It shows me a HP-internal Message that the Harddisk couldnt be started.
NO EFI Message or GRUB Message.
Is there any help on this forum ??
Sorry about my bad English. Hope, you could understand enough.