HD not recognized at all if AHCI enabled in bios - please help -

Hi,

I got a weird thing going on and have NO clue whats the cause.


I want to install win7 on a clean drive.... but I cant even get to the install options, because the drive is not recognized when i turn on the machine. It stalls, even before I can get into the BIOS settings.

I need to manuallly disconnect the drive > then change back to IDE mode inside the bios and now I am able to install Windows.

The funny thing... I have a backup image of a running WIN7 installation and if I copy it onto the exactly same drive it runs without problems in AHCI mode :shock:



does anyone have an idea what might cause the problem?

another weird thing.... i already installed win7 in IDE mode and thought that maybe later, once the installation is done i could switch back to AHCI... well, same thing.... once ahci mode was enabled in the bios, the drive was not recognized anymore.
i also tried to install the chipset drivers from within windows and got a "the system does not meet the minumum requirements." after searching a solution for this problem i found out that it wont install until i have ahci mode active.... ugh.... ; )

btw: its a gigabyte ga p35 ds4
and a WD Velociraptor drive

There are 6 SATA ports on the "South Bridge" controller (Orange ports). There are 2 SATA ports on the "Gigabyte SATA 2 Chip" controller (Purple ports). The orange ports use the generic Intel SATA/RAID drivers.

Which port do you have the hard drive connected to? Have you tried it in one of the the other ports?

That motherboard has a higher than normal number of complaints on Newegg. It could be defective.

Right now it's connected to the Orange ports.

But I'm pretty sure I also tried the other ones! ... have to try it again tomorrow.


what i still don't get is, that the same drive connected to the same port works without a problem once i use it with the old backup image.

I'm having a hard time wrapping my head around that also.

If you wiped the drive - used a utility that writes all zeros - and it was not formatted at all, then the drive should still be recognized by the BIOS. The IDE/AHCI modes should not affect the recognition of a drive at the BIOS level at all.

Load as IDE, and set the BIOS accordingly, and run W7 setup, formatting the drive at the prompt within setup.

Once formatted interrupt and restart W7 setup, and now use the prompt early in W7 setup to load the AHCI drivers; complete W7 setup. When finished, reboot, enter BIOS, enable AHCI, and that's it. Boot into Windows and choose your preferences and customisations.

I just did a new install in IDE mode, then tried to change to AHCI and had the drive not recognized. Did you enable AHCI in the registry as well as the bios? Once you do that, the drivers should be downloaded automatically the next time you restart.

If you install in IDE mode then change to ahci, it will not boot. But there is a way to do it. Enable AHCI is a tutorial on how to do the change. Follow the steps exactly and you should have no problems. However, it should see the drive in ahci at installation. But, you can still install in IDE mode and follow the above tutorial to change to AHCI.

Thank you for all the help and hints!

I tried everything... but in this particular case nothing worked.
While attempting to change the Registry settings i noticed that the correct settings were already applied!!?! eventhough there was still no chance to boot with AHCI active. So I figured something is really wrong and after three more wasted hours I finally grabbed the sledge hammer and manually wiped the MBR from the disk (which I did not want to do at first, because i read on several sites that this is not exactly a good idea to do that... FDISK /MBR)
anyhow.. this prog: TestDisk Download - CGSecurity made it very easy to do it all directly from windows (no floppy or BootCD was necessary) - I just hooked the disk up externally on another machine.
after that everything worked without a problem as it's supposed to and I was finally able to install Win7 with AHCI enabled in the BIOS.



Edit: btw.. the "AHCI enabling Tut" was a bit confusing for me. at part 3) "In the window that opens change the value to "0" and click OK." maybe someone should fix that.
I only was 100% certain what the correct setting was after I read the same tutorial again from another source where it was written a bit different and additionally a reg file was provided.

I'm happy you have it the way you want it, but you still should not have had the problem. At any rate, it is working now. Well done.