Hard disks are mechanical devices with moving parts, and as such will break down eventually, compromising any data stored on them that is not backed up. One technology that was developed to deal with this pair of issues is RAID (Redundant Array of Inexpensive Disks). The idea is to use multiple hard disks in the same system to provide both increased performance (by dividing up data so multiple disks can process different parts of it at the same time) and increased reliability by writing the same information to multiple disks at once. This technology filtered down to the enthusiast level a while ago, and has become a common feature on many motherboards, as well as an integral part of newer operating systems such as Windows 2000 and XP professional. In this guide, we will explore how the different implementations of RAID technology function, and how you can make your own RAID setup using a hardware RAID controller, or the software RAID function built into Windows XP Professional.