Devices not detected in windows unless in ACHI mode

PlumpMonkey · 1 Feb 2010 at 14:04

I have a Gigabyte EX58-UD5 motherboard on which I just reinstalled Windows 7.

I have all my HDDs and one DVD player connected to the Intel Raid Controller and one other DVD player attached to the Gigabyte controller.

When I installed windows I used the DVD player attached to the Gigabyte controller to install from the DVD. However I had to have have the controller set to ACHI mode in BIOS rather than IDE as otherwise Windows complained that I didn't have the required DVD driver during the install process. A quick Google at the time instructed my to change to ACHI and all was then fine.

However, since Windows was installed I set the Gigabyte controller mode back to IDE so I could boot off the Memtest CD. (Memtest doesn't support ACHI)

After this point the DVD player wasn't spotted in windows. I also just attached another HDD to the Gigabyte controller and this was seen in BIOS, but not in Windows again like the DVD drive.

I switched the Gigabyte controller back to ACHI in BIOS, and low and behold, both devices are now spotted by windows again.

So my question is this - Why doesn't windows see any of the devices on that controller when its set to IDE?

Ive seen other posts where people installed in IDE mode, and then have to tweak the registry in order to change to ACHI mode, but this is the other way around. And also the Windows disks are on the Intel Controller, and not the Gigabyte one...

derkaderka · 1 Feb 2010 at 14:18

So my question is this - Why doesn't windows see any of the devices on that controller when its set to IDE?

A stab in the dark guess ... Because they are features that are ONLY available
when in AHCI mode ?

PlumpMonkey · 1 Feb 2010 at 14:19

Perhaps I should have said that this DVD drive functioned ok on my last install under IDE mode.

derkaderka · 1 Feb 2010 at 15:21

Shift DVD to a sata controller that is Not in AHCI mode ?

PlumpMonkey · 1 Feb 2010 at 15:31

The other controller is in ACHI mode already.

I don't mind it being in ACHI, it works. I'm just interested into knowing why it no longer works in IDE mode.

Ive seen technical reasons why you cant flip a controller to ACHI if Windows was installed in IDE, but I've seen no mention of the reverse.

Im a guy that just likes to know "Why" really.

Hoodlum · 1 Feb 2010 at 15:35

PlumpMonkey said:
Ive seen technical reasons why you cant flip a controller to ACHI if Windows was installed in IDE, but I've seen no mention of the reverse.

Eh??? Is this older versions? Can do this fine on Windows 7

PlumpMonkey · 1 Feb 2010 at 15:49

Nope. Windows 7 included. This Mircosoft support article details it http://support.microsoft.com/kb/922976 and its been discussed on this very forum under threads like this

Hoodlum · 1 Feb 2010 at 15:55

PlumpMonkey said:
Nope. Windows 7 included. This Mircosoft support article details it http://support.microsoft.com/kb/922976 and its been discussed on this very forum under threads like this

Ahh I see, I already knew to change the reg key. I thought you were implying you "cannot" do it; my bad.

PlumpMonkey · 1 Feb 2010 at 16:01

No worries. That MS article says its only an issue for boot drives anyway.

This is that any device attached to the other controller when its set to IDE mode isnt detected by windows at all.