|Is this a laptop?|
Are both your CD drive and hard drive IDE type ( wide ribbon cable). If so, are they both connected to the same IDE cable? If so, check the jumpers on both drives. Hard drive should be Master and the CD drive- slave. If the hard drive is a Western digital make sure the jumper is not set to Master alone, which is a special setting on Western digital drives.
Also, go into Device Manager and verify the IDE/ATA/ATAPI controllers are running in a DMA mode. Right click on each of the listings there and look under the Advanced tab.