Originally Posted by circuitmonkey 
This is good to know, as I'll be trying the same thing on the same mobo next week, did you have SP3 installed, not sure if this makes a difference, but the first time I tried this it didn't work.
Wow, after a lot of trouble I've managed to get it working on my ASUS P5E.
I had two XP pro SP3 boot drives that are swapped in an out, a WD Raptor and a OCZ Core SSD.
As the SDD was a fresh installation I desided to start from fresh so Rolled my own XP installation CD with the RAID drivers on there and successfully installed XP with with the two WD 1GB HDD in a raid 1 array.
So my next step was to print off the registry pertaining to the ICH9R chipset from the working (SSD) installation, and from the non raid compatible (Raptor) installation using mizaring's sollution as a guide.
I found the differences and created my own registry update for the Raptor drive.
I copied iaStor.sys found on my SSD drive to the Raptor drive and used the following code to update the registry on the Raptor:
Code:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CriticalDeviceDatabase\pci#ven_8086&dev_2822&cc_0104]
"ClassGUID"="{4D36E97B-E325-11CE-BFC1-08002BE10318}"
"Service"="iaStor"
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CriticalDeviceDatabase\pci#ven_8086&dev_2916]
"Service"="isapnp"
"ClassGUID"="{4D36E97D-E325-11CE-BFC1-08002BE10318}"
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CriticalDeviceDatabase\pci#ven_8086&dev_29e9]
"Service"="pci"
"ClassGUID"="{4D36E97D-E325-11CE-BFC1-08002BE10318}"
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor]
"Type"=dword:00000001
"Start"=dword:00000000
"Group"="SCSI miniport"
"ErrorControl"=dword:00000001
"DisplayName"="Intel RAID Controller"
"ImagePath"=hex(2):73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,\
52,00,49,00,56,00,45,00,52,00,53,00,5c,00,69,00,61,00,53,00,74,00,6f,00,72,\
00,2e,00,73,00,79,00,73,00,00,00
"Tag"=dword:00000019
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters]
"queuePriorityEnable"=dword:00000000
"BusType"=dword:00000008
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\PnpInterface]
"5"=dword:00000001
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port0]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port1]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port2]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port3]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port4]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\Port5]
"AN"=dword:00000000
"LPM"=dword:00000000
"LPMSTATE"=dword:00000000
"LPMDSTATE"=dword:00000001
"GTF"=dword:00000000
"DIPM"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Parameters\oromVersion]
"MajorVersion"=dword:00000007
"MinorVersion"=dword:00000005
"HotfixNumber"=dword:00000000
"BuildNumber"=dword:000003f9
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStor\Enum]
"0"="PCI\\VEN_8086&DEV_2822&SUBSYS_82771043&REV_02\\3&11583659&0&FA"
"Count"=dword:00000001
"NextInstance"=dword:00000001
All that was then required was a quick reboot and to change the SATA config to RAID from IDE
Job Done!
Hope this can help some people.