Setting up a machine to boot from PXE
For bare metal, it is enough that the machine’s BIOS supports network booting.
On a machine that has an operating system on the hard disk, the BIOS must be configured so that the network interface card is either the first boot device, or at least prior to the Hard Drive device. The example below shows one of reasonable BIOS configurations. If you don’t insert bootable media, the machine will boot from the network.
In some BIOS versions, you have to save changes to BIOS after enabling the network interface card so that the card appears in the list of boot devices.
If the hardware has multiple network interface cards, make sure that the card supported by the BIOS has the network cable plugged in.