Installing a second hard drive is not a difficult task. If you don't know how to install a second hard drive, we recommend you to follow this steps.
Firstly, turn off the computer and disconnect all power cords. Any screws or clamps which hold the computer case or panel should be removed. Find and remove all of them.
Now, you should access the interior of the computer case. So, remove the computer case or panels. Unplug the IDE ribbon cable and 4-pin power connector from the current hard drive. The computer case may have a removable hard drive bracket. In this case, take off the bracket.
Set the jumpers on the drive. Thus, the hard drive will be enabled to be a Slave drive.
Now, you should slide the drive into the drive bay and fasten it. There is usually a special system of slide rails in a computer case for easy insertion and removal from the drive bay. If the computer case contains a removable drive bay bracket, return it to the inside of the case.
Then, the IDE cable connectors from the ribbon cables should be plugged both to the old hard drive and the secondary hard drive. Note, the connector which is furthest from the motherboard and typically black should be attached into the primary drive. The middle cable connector which is often gray should be plugged into the secondary hard drive. Most cables are designed to fit only in a certain direction on the drive connector. Of course, it is convenient and you don't need specific knowledge to plug. But it may happen, a cable is not keyed. In this instance, place the red striped portion of the IDE cable towards pin 1 of the drive. Then, find the 4-pin power connectors from the power supply. Plug them to the power connectors on the hard drives.
So, the installing is completed.
For more information about installing process use the service manual that came with the hard drive or base on other schematic diagrams for the hard drive.