Hi! Presuming you've not disabled anything in BIOS, I wonder if your installation is using the wrong Hardware Abstraction Layer (HAL). Open Control Panel - Admin Tools - Computer Management. In there, click on Device Manager and look under the "Computer" category and ensure it says "ACPI". If it doesn't, you can update the driver for the entry to point to ACPI instead but I've never tried this in reality and I suspect it's rather a risk! You can also manually select the HAL type during XP installation in case the autodetect gets it wrong. It's accessed with a function key (which one escapes me at present) at the point where you can also install RAID/SCSI drivers. Best wishes, Andrew