【電腦】Turn win7 ahci mode on

原本再安裝win7的時候，如果你的BIOS沒有設成ahcimode，基本上win7是不會enable ahci driver的。這樣就會造成如果你安裝完之後在bios切到ahci mode 電腦會無法開機。

這時候就要再切回原本的mode，開機之後坐下面的動作把ahci driver enable。

1. Exit all Windows-based programs.
2. Click Start, type regedit in the Start Search box, and then press ENTER.
3. If you receive the User Account Control dialog box, click Continue.
4. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
5. In the right pane, right-click Start in the Name column, and then click Modify.
6. In the Value data box, type 0, and then click OK.
7. On the File menu, click Exit to close Registry Editor.

Please navigate to the article for more detail;

• Error message when you start a Windows Vista-based
  computer after you change the SATA mode of the boot drive:
  "STOP 0x0000007B INACCESSABLE_BOOT_DEVICE"
  http://support.microsoft.com/kb/922976/en-us