[arch-general] Difficulty installing UEFI

Folks: I have a 2017 Lenovo ThinkCentre M800 that I'm using to try to install Arch on a hard drive. I've formatted the drive (under Arch, using fdisk, with gpt partition, etc.), gone through the installation up to the point where I run grub-install with this command: grub-install --target=x86_64-efi --bootloader-id=grub_uefi --recheck The error(s): EFI variables are not supported on this system. grub-install: errors efibootmgr failed to register the boot entry: No such file or directory. This particular machine originally had an MBR disk in it, and I'm not sure if the BIOS supports UEFI. Should I give up on using this machine to install a UEFI Arch disk, or is there some workaround? Paul