What is your problem exactly? Did you connect the PSU and it didn't work, or are you just wondering about the cover? The PSU should have a 24-pin ATX connector and a 4-pin P4 power connector. The 24-pin goes into the corresponding socket on the motherboard, and the 4-pin will fit in one half of the 8-pin socket on your motherboard. Once those are connected, everything should work providing all of your components are in working order.