Quote Originally Posted by yenclas View Post
Hello !

I have a problem with P35 DS4 board.

I downgraded BIOS to F3 and when I start the computer, after detect all my HD's, systems said AHCI BIOS Not Installed.

I tried to upgrade to F4 again, and the problem still here.

Anyone know when I solve this problem ?

Thank you
There is an option in the bios to make hard drives look like IDE to the OS. If u previously had the option set to raid/ahci mode then that might be the problem. It defaults to IDE mode.