In order to configure your hard drive, make sure the cables are snug, plug in and turn on the computer.
You must enter the BIOS to complete the installation. This can be done by hitting DEL, ESC, F1 or another combination. This key or combination of keys will be defined by the manufacturer of the motherboard, and appear on screen during boot up.
The system BIOS will have a hard drive setup generally under advanced setup. Because of the multitude of BIOS that are in production, this can vary. Under the advanced setup, you will have options to detect the drive. Use these options to detect the hard drive. If this is the initial setup of the drive, you will need to change your boot sequence in order to boot to the CD/DVD. Save the settings (your BIOS will give indication on how to do this). Reboot the computer and place your CD/DVD for your operating system in the CD/DVD drive in order to start your operating system installation.
With Windows XP, you must have SP 2 slipstreamed into the OS CD/DVD. If you have an older version of Windows XP, your hard drive may be seen as only 127 GB even if it is is a larger drive. SP 2 or higher is required in order to see the full amount.
If your drive is not detected at all, recheck the drives and check your BIOS for AHCI (Advanced Host Controller Interface) or IDE Native mode. This mode will depend on your computer, the hard drive size and the motherboard. As a rule, you can generally leave the SATA settings on their default setting.
Have an older Windows XP CD? Use nLite to slipstream the service pack into your CD/DVD.
Also, you can learn more by reading this comprehensive how to Build a PC guide.