To solve the problem, all you have to do is reactivate this AHCI driver in the Windows registry before changing the controller mode to AHCI in the BIOS of your motherboard.
If your installed your Windows 7 or Windows 8 accidentally in the legacy IDE mode, and want to switch to the AHCI mode, Windows will not boot after you switch from IDE to AHCI in the BIOS. Here is how to fix it.
Disk controller for SATA HDDs and SSDs can operate in both AHCI and IDE compatible mode, and usually can be reconfigured in the BIOS setup. AHCI mode is faster, has more features, and totally makes sense for modern operating systems.