I bought a 4gb 1600hz Kingston ram stick to put in my asus x555la and after instalation it doesnt show in windos (10 64-bit) it only show the 4gb that was there before.I'v used memtest and it displays the ram and it show it is full working but windos is not displaying it.I'v unchecked maximum memory and still doesn't show.I'v used CPU-Z its show the ram under spd.The laptop supports up to 16GB and i have windows 10 64-bit that allows up to 128GBs