Installing a raid setup requires two or more hard drives and (if you don't already have one) an open SATA or IDE connector for each drive, which most new motherboards have integrated. Many high-end PCs sold in the last couple of years support RAID 0 and RAID 1, and some handle RAID 5. If yours doesn't, you can add RAID and SATA or IDE channels to any PC by installing a RAID adapter from a vendor such as Promise Technology, Highpoint Technologies, or Adaptec. A RAID 0+1 adapter that supports two hard drives costs less than $75, and a RAID 5 adapter for up to four drives is available at under $150.

Here are few RAID tips:

• If there's no room in your PC's case for additional drives, buy a RAID adapter with external SATA connectors, and place the drives in an external housing such as Addonics' $75 Saturn ExDrive.
• Windows XP Professional and Windows 2000 can act as a software RAID controller for striped RAID 0 configurations, but not for mirrored RAID 1 or RAID 5 setups. Though this may save the cost of a hardware controller, the Windows solution is slower, and Windows itself can't be installed on either striped volume. Browse to Microsoft's support page for more.
• Follow the hardware vendor's installation instructions carefully, and always back up before installing RAID devices; installation problems can destroy the drive's data. Check the vendor's Web site for driver updates and additional installation information before you start.
• If your RAID configuration uses parallel ATA drives, set each drive as a "master" on its own IDE channel to ensure peak performance.
• When installing Windows on a striped RAID 0 or RAID 5 array, you need a floppy drive to load your RAID drivers. For some reason, Windows looks for RAID drivers only on the A: drive.