Alright , I really need help. This computer was originally a Windows 8 hp until I got tired of that and so I downgraded it to Windows 7 hp..and yes it is 64-bit home premium which can hold 16 gigs o_o but yeah.. I popped in 2 sticks of 4 gigs into the ram and it still says I only have 4 gigs and only 3.47 usable.. please help?