Problem With embling asus P5GD1-VM?

I bought an asus P5GD1-VM.i installed a DVD Rom And a CD writer To one of its IDE ports that one of them is master the other Slave.I installed a IDE 80GB hard Disk that it is Master in IDE2.my power is 500W and 20PIN.i cant install any windows because it gives an error saying that "Setup did not find any hard drive installed.but it shows Maxtor STM80 in Bios Setup.can the problem occur because of power.what can i do?