First, give us the info of the system, BIOS, ect... and what type/brand/model of HDD. Did you already try the autodetect in the BIOS? Did you set the jumpers on the HDD correctly, did you connect the HDD to the data cable correctly?
All these questions are basic, so don't be offended by them. We need info to help you out.
EP, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS