Turn off the computer and unplug the unit completely. Some people unplug all the peripherals, some people don't.
Step2
Open the computer case. Each case is a little different, but have many things in common also. The best thing to do is to check for screws, and take out any screws that seem to be for the case. Most cases open by a larger panel on either side.
Step3
Once the case is open, the inner workings are exposed and the hard drive can be seen in its rack.
Step4
Make sure you can see which type of hard drive you are adding, either ATA or SATA. Serial ATA or SATA have a different plug and power supply then ATA, which is the small white plug and a ribbon cable, which is what this article covers.
Step5
Plug in the hard dive before you place it in the rack. Make sure you have on an anti-static wrist strap, so static electricity does not ruin your drive before you even save your first file. Make sure your hard drive is set to master. A small jumper at the back should be wither in the center position of the left position.
Step6
Plug in the hard drive to the mother board, in the slot next to where the main hard drive is plugged in. This is the IDE Controller slot and will make your hard drive the master of channel 1, channel 0 is the main hard drive. The ribbon cable has a plug with a formed end, that fit specifically into a hole in the plug on the motherboard. Don't press anything hard, that will damage the motherboard. All plugs go in smooth and tight.
Step7
Slide the hard drive into the rack above or below the main hard dive.
Step8
Replace all the items as laid out in steps 1 and 2, and plug in the computer. When you boot up the system you should see the hard drive in the My Computer window. Depending on how many other drives you have such as CD ROM's or DVD ROM's, your hard drive will have a letter such as E or F.
Enthusiast 
