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