That's not always the case. When I was building my first rig, I had the same problem. I found out I had the RAM put it wrong. You may have an older motherboard. If you bent the pins on the motherboard where the processor goes, you have found your culprit.
oh i thought you meant like the holes for the processor on the motherboard had pins. The processor pins are all straight. Thinking of just buying a new motherboard, psu and ram.