Please press [Del] key in POST screen to go to CMOS> Chipset> IGD Multi-Monitor> set to Enable.
Then press [F4] key to Save and Exit the BIOS.
After next boot to OS, you will be able to choose second monitor if plug two monitor at either two on-board VGA ports.
You can choose D-sub+DVI / D-sub+HDMI / DVI+HDMI for display combo.
