SATA Hard Disk as a Slave
b> An SATA hard drive is an internal hard drive that connects to your computer's motherboard. It is even possible to connect multiple drives to the same computer; however, only one drive can be the master hard drive; the other(s) must be slave drives. This is because the master drive has the operating system installed and must be used to boot up the system. When installing a new SATA hard drive onto your computer, you must set it as a slave.
Power down your computer and disconnect the cables. Remove the Phillips screws from the exterior of the computer case and slide the case open to expose the interior of your computer. Identify the hard drive at the front of your computer, then slide the new SATA drive in underneath. Insert the smaller power cable into the power port on the side of the SATA hard drive. Follow the power cable running out of the current hard drive and insert it next to it on the motherboard. Pull out the ribbon cable, which has three different connection ports: one on each end of the cable and one in the middle. The connection port on the middle inserts into the slave drive and is slightly different than the other two ends (the pins built into the port are in different locations than the other ends). Insert the middle connection port into the ribbon port on the back end of the SATA hard drive. Plug one of the opposite ends of the cable (doesn't matter which one) into the SATA connection port on the motherboard (your current hard drive is inserted here). Once connected, this completes your slave drive connection. Second SATA 2 Hard Drive as a Slave
b> Installing a second hard drive in your desktop PC or notebook is an option used to increase hard disk space without losing or transferring the data from your original hard drive. Using this method not only increases hard disk space, it also increases the virtual memory space for the Windows operating system, increasing operational efficiency. One of the ways in which a BIOS can recognize the second hard drive is to boot it as a slave drive, with the primary hard drive booted as a master drive.
Turn the PC off and remove the desktop chassis. Refer to the pin connector diagram. This is displayed on the sticker, on top of the hard drive, for the position of the slave pin. Place the plastic connector on the slave pin as detailed on the diagram. Connect the hard drive to the power and IDE/SATA cable. Ensure the other ends are connected to the motherboard. Use the screws to mount the drive. Replace the desktop chassis. Turn on the PC. Enter the BIOS, by default this can be done by pressing F2. If this does not work consult your motherboard manual. In the BIOS, press right until the boot device tab is highlighted. Set the slave drive to boot following the primary drive. Read the bottom line and use the relevant key to save the settings. Restart the PC.
Hope it helps. http://www.pcmech.com/article/installing-a-hard-drive-step-by-step/
Installing a hard drive.