CTRL-B required to activate NICs PXE Image?

[NiKiZe]

I see that you refuse to give information, try and understand your bios at all, or test the different options that could make a difference.

For any one else finding this:
Remove all other devices from the machine, if it has built in flash that boots which is not removable, make sure it has a bootloader that exits so it goes on to the next device.
And play around with all bios options. Some options do more than it says it should do, so in the case above having all nics and boot roms and able to see if that changes which other options becomes available after restart would be good thing.

And if all else fail, use appropiate ipxe.dsk to put on the disk and avoid unnecessary emulation by using the .iso version.