http://www.nirsoft.net/utils/product_cd_key_viewer.html
cat /sys/firmware/acpi/tables/MSDM
xxd /sys/firmware/acpi/tables/MSDM
hd /sys/firmware/acpi/tables/MSDM
/vía: http://www.sysadmit.com/2015/07/windows-uefi-bios-ver-clave-guardada.html