I just got another 8GB kit of ram in the mail today.
It is the exact same set as my previous ram only a different color
4x 4GB 1866Mhz (9-10-9-27) DDR3 ALL ram sticks are the exact same epec.
(I have a red & black kit)
When all 4 sticks (16GB) are in the bios detects all 16384MB and boots fine, but in windows it's only allowing me to use 12GB, I did not have this issue before.
It's not the new ram, I'm writing this using the new stuff and everything is peachy, It's only when they're all in there. It';s not the slots either, I've switched them around