First you should provide a litle more information.
When did this problem occur? Has the drive worked properly before? Or did
you installed it only recently?
What type of pc is it and what type of motherboard do you have?
Which IDE channel do you use, what other IDE components are connected?
Is the CD drive connected as master or slave? What is the master/slave
setting on the other devices?
Besides that you can:
- check if all cabling is properly connected;
- check the site of your motherboards manufacturer for BIOS updates.
