the first thing that i would suggest is that you open up the computer and have a look to see if the wires have come loose (that plug into the cd drive)
if the wires are fine then check that the jumpers on the drives are set to 'master' not 'slave'
if that doesn't work you could get onto your BIOS setting and make sure that they are enabled on there
if none of this helps let me know and ill try do some research into it
