AHCI Causes BSOD (blue screen of death) Solution:

Sometimes, people install Windows 7 without AHCI enabled, only to find out that enabling it after the install causes a BSOD. To fix this, you have to edit the registry.









Press Windows + R key, type regedit, then navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci. Then right-click the word Start on the right-side and click Modify. Change the value in the window to “0” and click OK. Exit Regedit, reboot the system, and change your SATA controller to AHCI; you will boot right into Windows.