Greeting.   I ran across this the other day and immediately thought of this website.  Its one of those things that I will use now, then forget about and in six months to a years time when I need it again, it’ll be gone.

I hadn’t bothered to use the AHCI drivers when I installed Vista a while ago, but I’ve been hearing more and more how its a good thing (as long as your hardware supports it), or more to the point, the NCQ is a good thing.

Some time in the past, I tried to get XP to switch to AHCI after install but never had any luck; there are instructions out there and I don’t doubt they work for most people, but I either had some sort of incompatible hardware or pebkac (problem exists between keyboard and chair) going on because it just wasn’t meant to be.  After that incident I’ve been a bit leery of AHCI.

Anyway, I decided to try it all again and this time it was remarkably easy to do.  Just a simple registry tweak, reboot and change your SATA controller to AHCI in the BIOS and that’s it.  I was reasonably impressed that it went so smoothly.  I”m still waiting for some catastrophic data corruption; I’ll let you know if that ever happens.

I’d rate this a 3 on the difficulty scale, and a 6 on the potential bad idea meter.

Instructions:

1. Go to: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
2. Modify Start
3. Change the value to 0
4. Reboot
5. Go into bios and change sata controller to AHCI (its probably on IDE right now)

That’s it.

Reference (from Microsoft):

http://support.microsoft.com/kb/922976