Well the first question would be if it is a IDE or a sata connection. If it is an IDE which is a wide strap connecting the hard drive to the mother board, then it may have two connections available on the one strap. If it doesn't there may be a space for another strap or you can change the one you have to have two connections. The main hard drive goes on the end connection and the second storage one on the middle. Now IDE hard drives have jumper pins at the back. A diagram will be on the hard drive. Make sure the main one is on master and the second one on slave, or both on cable select if the main hdd is on the end of the ide. This should make it boot to the main hard drive and you can just format the second hard drive from there.If it is sata. You will usually need another connnection on your mother board to plug the second hard drive in. Then in the bios you can set boot order and so on.