prior to the 'no 80 conductor cable installed' error displayed were you inside your case changing drives etc?
can you tell us what motherboard and hard drive model and size you have?
click here click here may help a bit. check the jumpers are set to master or cable select on your hard drive and master & slave correctly on you optical drives. try reversing the cables or switching the cdrw cable with the hard drive cable and see what happens. some more info may help here please.