Thanks. New built. MSI Z87-G45 motherboard, Viper patriot 16 gb DDR3 pc3-17000 2133mhz, i5-4570 3.2 ghz intel processor, 500w power supply. Tried one chip on slot two and both chips on 2&4. Also tried swapping the chips around. Also could not load win and had to wipe the HDD something about MBR. But still no luck getting Win 8.1 installed.