Asus Motherboard P5S-MX-SE with intel Core 2 duo 2.2 GHz

I have a motherboard ASUS P5S-MX-SE with intel core 2 duo 2.2GHz with 1GB DDR2 400 MHz Ram and my motherboard supports DDR2 upto 667MHz

So for increasing performance i have purchased a 2 GB 667 MHz DDR2 Ram and installed it i.e. 1GB 400 MHz Ram(old) in one slot and 2GB 667 MHz new Ram in another slot.

Now issue is my both rams showing running at 333 MHz speed only on testing both at a time and seperately as well, However the motherboard support DDR2 upto 667 MHz.

How can i optimally use to get best speed out of it without doing the overclocking which may lead to heating?

Can i run windows 10 on this system??

Answer

Attribution
Source : Link , Question Author : Vinod , Answer Author : Community