More than likely your Power Supply plug/cord has a ground (the round terminal, green wire). When pluged into the wall socket the PC is grounded, no static electricty.
so you mean my motherboard and cpu already destroyed?
Well, you haven't really given that much information, so I guess I can't make that assumption, but if you've changed all those parts and it still doesn't work, it's either that, or your motherboard might be DOA.