In ICH5 spec v1.0, "It is recommended that BIOS limits the maximum UDMA mode to 5 when programming drives even if some of the drives report that they support mode 6 or above. Although this has no impact on the actual data transfer rate between the drive and the SATA controller, doing so will be consistent with ICH5 PATA spec and compatible with OS drivers." Windows XP OS could not detect SATA as right type. We suggest you can set the enhanced mode in the BIOS to install Windows XP OS. The SATA HDD will go through the ICH5/ICH6 SATA channel.