Go into BIOS

Change Network Card to Enable PXE Boot.

eg under Integrated Devices

Mouse down to Embedded Gb NIC1 and press right arrow

You should now be able to press CTRL + S at boot time and enter the broadcom setup screen

Enable WOL by changing Pre-boot Wake On Lan to enable

save with F4 and reboot

Go back into BIOS and check your boot order eg change USB or HDD to boot up 1st if your not booting from PXE

save and reboot