I just build my PC and took it to a computer shop to make sure everything worked, they installed everything and updated the drivers. I've looked around some threads and my Asus Z87 motherboard says "AO" which isn't a bad thing. I've had to buy a 24+4 DVI-I to a VGA adapter to connect it to my monitor. Whenever I start up my pc the monitor shows the ASUS and windows 8 symbols. Then the screen just turns black and I can't do anything. What do I need to do?