It's possible that the CD or DVD that you put in is damaged itself, and your drive is fine. Have you tried using the same CD's/DVD's in any other devices, such as a DVD player? If the disk also does not work for the other device, then something is probably wrong with the disk. If the disk does work in a different device, however, then something is wrong with your laptop's optical drive. Please reference the following link if this is the case. Dell Inspiron 1545 Troubleshooting