Help! Aspire 8920, updating SATA drivers after XP install to change IDE to AHCI

Dear all,

I'd be grateful of some clear advice.

I have intalled XP pro on an Acer Aspire 8920 (The label says 8920G but in the F2 menu it hasn't got it). To do so I switched SATA mode to IDE as in AHCI it could not detect the harddrives (dban nuked prior to this)

Before I install SP3/other drivers or put time into doing anything else with it, I would like to switch back the AHCI. As far as I know, to do this I need to install the correct SATA drivers. If it goes wrong, I'm aware I have to start again, hence the need to sort this out first.

Acer provide only Vista drivers. I however found a acer-dedicated site that listed drivers for xp. Therefore I believe this to be my best shot at having the right drivers. However, despite lengthy reading, I cannot for the life of me work out how to install the new SATA drivers.

My device manager reads this:

IDE ATA/ATAPI controllers
-Primary IDE Channel
-Primary IDE Channel
-Secondary IDE Channel
-Secondary IDE Channel
-Standard Dual Channel PCI IDE Controller
-Standard Dual Channel PCI IDE Controller

I have no idea which of these to update, what file is relevant to each, and of course when instructions refer to fding 'AHCI' or 'RAID' drivers, this is not present.

In the file of SATA drivers I downloaded, I have files including
iaStor (setup information)
iaStor (system file)
iaStor (security catalogue)
iaAHCI (setup information)
iaahci (security catalogue)
TXTSETUP.OEM

Can anyone make sense of this for me and advise me as to how to perform this procedure?

Alternatively, if someone has a different (tried and tested) source of drivers/has already done this/has another (straightforward) way then I am all ears.

I am not a computer genius, I simply learn what I have to as I go along, so please advise me in simple/step-by/step terms that I can follow.

Thanks
Eddie T