With RAID, isn't it always constantly mirroring the data between the 2 hard drives? If you installed something you regret, how can you go back? With Ghost, I image my clean installed XP OS with the latest patches, and restore the image whenever my OS goes tits up. Restoring the image is better than formatting and clean installing, cos it only takes 3 Minutes to restore!! Beats the hour long formatting and installation of XP!