Make sure the jumpers are set correctly. Technically you should have your hard drive on the end of the cable (master) and your CD rom in the middle (slave). You can go around this by properly setting the jumpers on both drives. There should be a diagram on the top of both drives indicating how to place the jumpers on the drives.
You really shouldn't put your CD/DVD rom on the same channel (cable) as your hard drive - it slows down the data transfer speed.
Okay, i see you have a SATA drive in there so disregard my last comment.
Right click My Computer -> Properties -> Hardware tab at the top. Click on Device Manager. Under CD drives yours should be there. Right click on it and choose Uninstall driver. If it isn't there look for a section with a yellow exclamation mark. This means the driver did not install correctly the first time.