Ok I now have installed 4 more GB's of The same Kingston Hyper X ram as I had in my system before , KHX8500D2T 1K2/4g X 4 sticks . Here is the big problem it will not run at 1066 MHz . Why ??? It acts as if it wants to boot but hangs . I even set every thing to stock speeds and tried it like that , no go . It runs at 890MHz or even 800 MHz just not 1066 . Is this becasue I have all 4 slots occupied ?