I have an OptiPlex 755 that was made for Windows XP and Windows Vista. I downloaded the SATA AHCI "pre-OS install" drivers from https://www.dell.com/support/home/us/en/04/drivers/driversdetails?driverid=xdm29&oscode=ww1&productcode=optiplex-755
It contains these files:
iaahci.cat iastor.cat IaStor.sys Version.txt
iaahci.inf iastor.inf TXTSETUP.OEM
I can load them in BIOS AHCI mode during the Windows XP setup from a floppy drive, or after Windows XP installation in BIOS Legacy mode by manually replacing the Standard IDE Channel driver on a running Windows XP system, then rebooting and switching BIOS mode to AHCI. Both methods work.
Now I got a POSReady 2009 DVD, so I wanted to use it and install the AHCI driver in the same way. But, POSReady 2009, would display an error message upon reboot: "Operating system not found" (similiar to that)
So, I wonder why the driver wouldn't work for POSReady. There must be a difference that makes the reboot fail. Do you have any ideas? And could I make the AHCI driver files compatible with POSReady?
And there is a second problem: The chipset drivers (https://www.dell.com/support/home/us/en/04/drivers/driversdetails?driverid=njm0j&oscode=ww1&productcode=optiplex-755) refuse to install on POSReady. But that is probably a matter of changing some string in the Registry I suppose. What's really urgent for now is the AHCI driver issue.