I have a Lian-Li PC-K62 case and it has 4 fans and they all have 4 pin molex adapters on them and my motherboard, Asus M4A87TD Evo has one 3 pin connector which all the fans without the adapters are 3 pin, where do I plug in the molex?
You can plug them into any molex connector from the power supply harness. That is the same +12V that the board supplies. The 3rd pin on the board is for speed feedback, and the 4th pin is for speed control. None of which you need.