Before formatting the systems hard drive, there are few items one should carry out.
    Please read over the checklist below:
        Backup any information that may be important. Formatting will in a sense erase the hard drive of all its data (unless you want pay UniDataRecovery to recover your data!). Even after a high-level format, data can be recovered. If erasing all data from the hard disk is required please visit UniDataRecovery data eraser section. Meanwhile for Hard drive formatting please follow the following protective steps to avoid deleting required data:
        Gather all of original CDs and disks and any documentation that came with computer.
        Gather any additional software that may be required to reinstall.
        Go to "Device Manager" on system, copy down and make a list of the devices and/or the drivers that are being used.

    Note : If the computer system came with a "Restore Disk" from the computer manufacturer, be sure to use it instead. The information on that disk should have everything needed to repartition, format and reload software to its original condition.

         If Windows XP is to be reinstallfrom a CD, the installation instructions will guide through re-partitioning and re-formatting the drive. The following instructions are for those who wish to go through the manual process of formatting a hard drive.  

         Once the above checklist is completed, then formatting the hard drive can begin the next step of reinstalling your machine's operating system.