Answer by jrwren for Ubuntu 10.10 / Debian preseed keyboard origin seed

from: https://askubuntu.com/questions/89185/what-is-the-correct-way-of-setting-up-an-abnt2-keyboard-layout-in-preseed/258570#258570

AFAIK you need all of

d-i     keyboard-configuration/variant select English (US)d-i     console-keymaps-at/keymap select usd-i     keyboard-configuration/xkb-keymap select us

and possibly

console-setup/ask_detect=false console-setup/layoutcode=us keyboard-configuration/xkb-keymap=us

on your append line of txt.cfg (or whatever isolinux config)