If you receive the boot blue screen error STOP 0x0000007B INACCESSABLE_BOOT_DEVICE there are three ways of resolving this:

Reinstall windows: Unfortunately XP will require drivers to be loaded before windows is installed in order to use the advance AHCI functions of the motherboard. This will require either utilizing a compatible USB floppy disk drive or attempting to create a slip streamed version of window XP with the drivers integrated. Vista is different slightly and you may attempt solution number 2.

Repair install windows: Vista and future operating systems will have better computability with regards to native drivers for the operating system. You can attempt to try restoring the operating system by using the windows advance repair options from the windows vista DVD. Please review Microsoft’s documentation regarding this. XP cannot utilize this function unless the drivers are slipstreamed in to the installation disk as suggested in part one.

Enable IDE compatibility mode: If neither options resolve your issue and allow you to get back in to your preferred operating system then please revert the changes in the BIOS to IDE MODE.

 

Further review: