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