Do not reinstall the system, open ACHI

I believe many of my friends have encountered Windows Vista or Windows7, and then open the AHCI function of the SATA hard drive in BiOS, it will not start. I recently encountered this problem when I started installing AHCI after installing Windows 7. Only after changing back to IDE mode, the system will return to normal. After testing, I found that if I installed the Windows system in IDE mode, I need to reinstall the system to change the hard disk to AHCI mode in BiOS. So is there a way to open the AHCI mode of the hard disk without reinstalling the system? After some research and search, finally found the following methods, share it: Open the AHCI mode after modifying the registry 1. Click the "Start" button, type "regedit" in the search box, press the Enter key to open the "Registry" Editor window. Although Windows 7 does not display the "Run" command by default in the "Start" menu, it can actually be replaced with a search box (or directly by pressing the Windows key + R key).

2. In the title bar on the left side of the Registry Editor window, navigate to the HKEY_LOCAL_MacHINE\\SYSTEM\\ CurrentControlSet\\services\\msahci branch, then in the right window, double-click Start.
3, in the "Edit DWord Value" dialog box, change the value in the "Value Data" box from 3 to the number 0, click the "OK" button.
4, close the "Registry Editor" window and restart the computer.
5, enter the BiOS settings interface when restarting the computer, change the hard disk to AHCI mode.

After modifying the registry and enabling the hard disk AHCI mode as described above, you can start it normally without reinstalling the system. Although the startup speed of the computer will not change, when you copy a large number of files, you can see that there is a certain acceleration effect. The hard drive score in the Win7 system score should also increase a lot:)