This document describes installing native Serial ATA (SATA) drives on a computer that is using Windows Vista. Computers built for Windows XP use native-ATI technology to control hard drives, while Windows Vista uses native-Serial ATA (SATA) technology. Installing an ATI hard drive on a computer with WINDOWS Vista will cause compatibility problems.
Also, if a computer is downgraded from Vista to XP, it may display an error message that the operating system cannot locate a hard drive. If the installer cannot locate a hard drive, it cannot install the XP operating system. The BIOS on a Vista computer is configured for a native-SATA environment and it cannot recognize ATI drivers. It may be possible to override or change the BIOS settings to allow XP to recognize the hard drive.
note:.If you are considering downgrading a computer from Vista to the XP Operating System, see HP Notebook PCs - Problems with SATA Drivers When Downgrading From Vista to XP