Make sure the data cable is FULLY INSERTED into the back of the drive AND INTO THE MOTHERBOARD.
Now, does it show in BIOS?
If the drive shows in BIOS, do you have it set to be the primary boot device?
I recently upgraded my PSU to an Antec TP2-550W-EPS12v. Everything seems to be working, except for the CD-RW/DVD-rom. I have disconnected, reconnected IDE cables and power cables. It using the 4 pin MOLEX connector and I have tried each one that the PSU has. I am trying to do a fresh install and I cannot get the drive to read the cd. Any suggestions?