Firmware Settings: BIOS & UEFI

Getting into the right place

Spam the vendor key during power-on:

Vendor Keys

Most laptops (Dell/Lenovo/HP)

F12 / F9 / Esc for one-shot boot menu; F2/F10/Del for setup

Motherboards

Del or F2 for setup; F8/F11 boot menu

VMs

Esc during splash (VirtualBox/QEMU)

One-time: boot the USB

One-shot boot menu → pick your USB stick (UEFI entry preferred on modern machines — matches how you’ll install).

Settings worth checking once

  • Secure Boot → Disabled (Arch-family standard; can be re-established later with custom keys).

  • SATA mode → AHCI, not "Intel RST/RAID" — Linux drivers target AHCI; switching later means reinstalling Windows too, so decide NOW on dual-boots.

  • Fast Boot (firmware flavor) → Off, so USB init completes.

  • TPM → leave alone unless BitLocker complains (then suspend BitLocker per Installing Alongside Windows).

  • Boot order — set disk-first afterwards so GRUB owns boot.

Legacy BIOS machines

Everything above minus Secure Boot. Installer will use msdos partition tables automatically; keep single-disk installs simple this way.

After install

If firmware boots straight to old OS: reorder entries — either in setup, or from Linux:

sudo efibootmgr -v                  # list
sudo efibootmgr -o 0003,0001        # put AcreetionOS first