Sie wrote: Is it a SCSI or IDE drive? Is it on its own channel or shared? Do you have the jumpers set correctly? (ie you havent got two devices set to Master) Are the BIOS Boot Options setup correctly? Have you checked the cabling and swap tested cables if possible?
Check the IDE Ribbon cable, it connects to your motherboard one end and CD/HDD on the other. Is it just your HDD thats on that cable? If not remove the other device and try again. If there are more than one device on the Cable you need to ensure both are setup correctly with their jumpers. (IE HDD Master, CD Slave)