Richard Owlett composed on 2025-12-28 09:52 (UTC-0600):
Joe wrote:
First question: BIOS or UEFI booting? This is at hardware level, before
the OS is involved. Completely different boot system.
I assume BIOS as machine is a Dell Latitude E6410 {IIRCC introduced ~15
years ago}. GParted reports partition table as "msdos".
Is there a way to double check on a running machine?
# efibootmgr
EFI variables are not supported on this system.
Above result means you have legacy booted. A command not found response is highly
likely on a legacy booting installation.
# efibootmgr
BootCurrent: 0001
Timeout: 1 seconds
BootOrder: 0000,0001,0002,0003
Boot0000* debian
Boot0001* UEFI OS
Boot0002* Hard Drive
Boot0003* CD/DVD Drive
Above is from a UEFI boot where only one OS has been installed and is registered
bootable in the firmware.