Tech21

The Acer Aspire 7738G notebook is shipped with Windows Vista Home Premium SO.
A friend of mine bought this (good) notebook but wanted to downgrade to Windows XP.
The first thing I made is to check if drivers are available:

http://www.acer.com –> Support –> Drivers –> … –> YES! They are!

So download all of them and extract on a USB Key (you can also burn a CD).
Then, the second thing is to find a solution for the AHCI Controller.

To properly boot WIndows XP CD, first enter the BIOS and change SATA Controller Mode from AHCI to IDE. In this way, a normal Windows XP boot CD can load, otherwise you have 2 options:

1) Download SATA HCI Drivers (see below), create a driver floppy disk and on Windows XP boot start, hit F6 and load custom driver
2) Using nLite create your own Windows XP copy with AHCI driver already preloaded.

Method 1 requires a floppy driver, I have none! Method 2 is time consuming, so I prefer to try another way.

After enabled IDE mode for SATA drivers, I installed Windows XP as usual: the only thing to take care is to use the “C” partition, the “Acer” one, because the “E” partition and the “unnamed” partition contains recovery information, so avoid to touch them.

Wait until Windows load…

At this point we need to enable the AHCI SATA mode.
Download the latest version of Intel Matrix Storage Manager here:

http://www.intel.com/support/it/chipsets/imsm/

Since we want to change drivers of a boot hard drive, a standard installation would not have success. So we need a little more work.

Unpack with “-a” command line option: cmd > iata88cd.exe -a

It will unpack all files under “Program Files > Intel > Matrix Storage Manager”.
Look for the folder “Driver”, or Driver64 if you need drivers for 64 bit.
Copy iaStor.sys from this folder to C:\Windows\System32\Drivers folder, overwriting the existing one.

Now, open Device Manager (Control Panel > System > third tab) and select the Intel(R) ICH9M/M-E 2 port … 2928 controller.
Right click, update drivers.
Force to load drivers from the Matrix Storage Manager Driver folder and select the iaahci.inf file. Click next and select the right controller, in this case it is the Intel(R) ICH9M/M-E.
Windows now says that the driver can be harmful, but trust me and go on.
When installation is finished, reboot the system WITHOUT touching the second controller (292D).

Now enable from the BIOS the AHCI mode.

Windows should start well and now it will let you install the standard Intel Matrix Storage Manager installation procedure.
Reboot the system and now you have only one AHCI enabled controller!

NOTES:
At one moment I have tried also to follow another procedure, with a little regedit phase.
I’ve launched this code from a hci.reg file:

Windows Registry Editor Version 5.00
 
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CriticalDeviceDatabase\pci#ven_8086&dev_2922&cc_0106]
"Service"="iaStor"
"ClassGUID"="{4D36E96A-E325-11CE-BFC1-08002BE10318}"
 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor]
"Type"=dword:00000001
"Start"=dword:00000000
"Group"="SCSI miniport"
"ErrorControl"=dword:00000001
"ImagePath"="system32\\drivers\\iaStor.sys"
"tag"=dword:00000019
"DisplayName"="Intel AHCI Controller"
 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters]
"queuePriorityEnable"=dword:00000000
 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Enum]
"0"="PCI\\VEN_8086&DEV_2922&SUBSYS_B0051458&REV_02\\3&13c0b0c5&0&FA"
"Count"=dword:00000001
"NextInstance"=dword:00000001

USEFUL LINKS:
- Some details on Acer Aspire 7738g
- Intel Matrix Storage Manager
- HWUpgrade forum (italian) speaking about it
- English forum speaking about it