Check if your motherboard supports the speed of ram you have and try putting one stick of ram in , see if your pc boots. If it does then stick in the other ram on it's own to test if it's anything wrong with your ram sticks.
Hope it helps !
Hi there ihsaan96 thanks for your reply. I have already tried both ram sticks by them selves & i get the same result, the MB says it supports 1333,1066,800mhz at 1.5v with a maximum capacity of 8gb ram & the sticks i bought are just that 2x4???i am at a loss???. The ram i am using at the moment are 2x2 KINGSTON DDR3 1333mhz 1.5v & they run perfectly??? If you have any more suggestions PLEASE PLEASE PLEASE let me know thanks