Connect the Hard Drive

Assuming your hard drive(s) has already been physically installed in the system case, you must now connect it up to the power supply and motherboard.

Attach the power cable. Choose an unused power lead from the power supply and plug it into the power plug on the hard drive. The plug will be keyed so that it will only go in the correct way.
Attach the ribbon cable to the hard drive. The ribbon cable goes from the primary IDE controller of the motherboard to the drive. Make sure the red edge of the ribbon cable is in line with Pin 1 on the drive. If you can’t see Pin 1 marked, then it is the pin closest to the power connector. If you place the cable on backwards, you may get strange errors that make your new drive sound like it has died already. If you are adding a second drive, simply choose a connector on the same ribbon cable that is not used. Most ribbon cables come with two connectors: one on the end and one mid-way. In this case, it doesn't matter which plug goes in what drive. The computer looks at the master/slave jumpers to see which one is “C”. Make sure to connect the other end of the ribbon cable to the primary IDE connector on the motherboard. Pin 1 will be labeled on the motherboard, and align the red edge of the cable with it. Also, ATA-66/100 drives must have an 80-wire cable instead of the older 40-wire’s. The ribbon cable will generally be included with the hard drive.
Double-Check your work. Make sure everything is tight.