Windows 7 The Dreaded AHCI Issue with a Twist...

[Mark Hummel]

Hello;

My first post. I normally run Win7 from a mechanical HDD. I recently added an SDD for another operating system and changed my BIOS to configure SATA drives to AHCI. WIN7 is still on it's original HDD.

Everything I've read about win7 and AHCI mode is more than a year old. Is there an easy method that will allow WIN7 to live on an AHCI-enabled HDD?

Would it be better to reinstall Win7 onto the HDD?

Mobo is an ASUS M4N98TD EVO. Please advise.

 

[voyager]

I assume what you're saying is that you want to move your Win7 OS install from a disc HDD to a SSD with no other changes.
Correct?
If so:
Your Win7 install will have to have an F6 AHCI/RAID driver install if you want AHCI.
If your original install has that driver install, you should be OK to make an image of your OS partition and then load it onto the SSD.
If it does not have the F6 install, you will have to do a Win7 clean install on the SSD including the F6 driver install.

 

[Jimbo22]

Excellent advice by voyager, the key point to remember like voyager points out. If the ACHI driver is not installed and enabled in the BIOS before the OS is installed you'll get the dreaded BSOD upon rebooting. Also, if you plan on using larger HDD greater that 2TB you must have AHCI enabled this is do to the limitations of the SATA drive controller. For SSD's, the AHCI driver helps with performance.

 

[Saltgrass]

There are several places on the net that explains how to change over. This is one of them.

Guide Change from IDE to AHCI after Installation

I suppose the important thing is to make the change in the registry before you change the Bios to AHCI.

 

[Mark Hummel]

I assume what you're saying is that you want to move your Win7 OS install from a disc HDD to a SSD with no other changes.
Correct?

No it's not correct. I have no intention of installing Win7 onto my new SDD. As I wrote, "I recently added an SDD for another operating system..."

My question is to find out which is the better solution for AHCI compatibility: Reinstalling WIN7 onto it's (original HDD) or modifying the registry on the current install. Please advise.

 

[Saltgrass]

The OEMs say it is better to reinstall than change the controller from IDE to AHCI. I think the newer systems do not have the problems some of the older ones did. I just tested using the original Windows 7 DVD and installed using IDE and then changed to AHCI. The registry did not need to be modified since the msahci entry was already set to 0.

I only had to reboot once after booting with AHCI enabled to finish the change. My install did not have the Intel Rapid Response Technology yet installed. I would just plug in the drive and try it, by itself in you want to make sure the other drives are not effected.

 

[Mark Hummel]

Thank you Saltgrass. Actually, I did install the SDD for the other OS. When I switched my BIOS to ACHI, Win XP started to boot than BSOD and an automatic reboot (I set BIOS to autoreboot on error). I've wanted to install Win7 anyway so this is probably a good time to do so.

Process: Set BIOS to ACHI and install Win7. If it "sees" the drive, I should be good. If it doesn't, then what?

 

[Saltgrass]

I am now a little confused...when did Win XP get into the discussion? It would need the drivers Voyager is referring to, but Windows 7 does not.

AHCI is just an improved driver. The drive itself doesn't care, usually. If you are using an older drive..and I mean old, it might come into play. But you should be fiine. If something does go wrong, try cleaning the drive with the Diskpart Clean command. which will of course wipe the drive.

 

[Mark Hummel]

I am now a little confused...when did Win XP get into the discussion? It would need the drivers Voyager is referring to, but Windows 7 does not.

Sorry, I didn't mean to "muddy the water." I have the choice of win7 or XP and like you wrote, the drive doesn't "care." Your tip on the drivers though does help. So to make sure I'm not confused;

A reinstall is the preferred method. If win7, the drivers should be on the install disk whereas for XP, I better have some drivers on-hand just in case.

Drivers are not something I'm used to worrying about or even thinking about much with Linux. Thank you for the guidance. It is appreciated.