Sorry. I ask this because the system in question is dual-boot FC6, and hence there might be someone who's experienced the same problem. Otherwise, please accept my apologies. A fully functional dual-boot FC6/Windoze XP system had its MB replaced. On being returned (and the disk reinstalled) it booted FC6 just fine, but XP could not find the disk. Not that it just would not boot, but that under no circumstances (CD boot, ASR boot, normal boot) could XP find the disk. The disk partitions are: 1 - NTSF, 2 - /boot, 3 - /. Any suggestions as to what might be missing? FWIW, the disk is SATA, and, yes, the driver disk was provided at the appropriate time. Thanks.