You have to run the Microsoft FIX to switch to AHCI.
Go from IDE mode to AHCI mode for your SATA devices by running the Microsoft Fix It tool to enable AHCI driver support.
After running the MS Fit It Tool, reboot, enter the BIOS, change your controller mode to RAID AHCI, save the BIOS settings and reboot back into Windows.
Microsoft Fit It Tool – Enable Sata AHCI mode
After you use the BIOS setup of a Windows 7-based computer or a Windows Vista-based computer to change the Serial Advanced Technology Attachment (SATA) mode of the boot drive to use either the Advanced Host Controller Interface (AHCI) specification or redundant array of independent disks (RAID) features, you receive the following error message when the computer is restarted:
STOP 0x0000007B INACCESSABLE_BOOT_DEVICE