I have spinning HD Drive not recognized in IDE mode in the BIOS by my mobo. But if I switch to AHCI mode the drive is show in the BIOS. The drive is a WD 300GB raptor, and the board is a Gigabyte P55A. I had been messing around with moving and changing sizes of partitions on this drive. There is no data on the drive. I used G-Parted to wipe the drive again, and wrote a new partition table. Still no luck in the BIOS. I want IDE mode so I can but XP on this drive. I've changed channel connections between the drive and Mobo, and still nothing in IDE. This drive used to be able to been seem in IDE mode until I started move partitions around on it.