Hey vandiesel, try the BIOS dated from 1/13/09 again (The later BIOS has an option called Core Leveling, which locks the processor into single-core or dual-core only). Then double check your chipset settings for IDE/AHCI. It should be on Native IDE. Also with windows XP I believe there was a patch that later enables multi-core support, which is probably the one that is giving you issues.