i have a uefi class 3 laptop
acer travelmate p2154-52
i trying to install win7 on it using flashboot and by adding modified acpi.sys
and when i trying to boot setup
IT STILL SHOWS A5 ERROR
also safemode stoped on ahcix64s.sys
UPD: i think that the problem is with storage drivers but i don’t fully understand what should i do next…
VEN_8086&DEV_02D3
help me please
By HW device ID, the issue is the Intel(R) 400 Series Chipset Family SATA AHCI driver… not released by Intel for Windows 7/8.x, so no official driver to download.
@kosfurler
Please look into the first post of >this< thread and download the driver named “Universal 32/64bit Intel RST(e) AHCI driver v15.9.8.1050 mod+signed by me”.
The driver should work with Win8 and Win7, but cannot be used for the OS installation (WHQL stamp is missing!).
still ahcix64s.sys in safemode 
@kosfurler
How did you install the mod+signed Intel AHCI driver? Has the Win-RAID CA Certificate been imported beforde starting the driver update?
Win-RAID CA Certificate? i just installed it through dism
so I understand
but how to do this if windows doesn’t boot?
via setup’s shift+f10?
Haven’t you opened the driverpack after having downloaded and unzipped it?
There is a file named “How to import the Certificate.txt” in it.
Since Win7 has a generic AHCI driver named msahci.sys in-the-box, a missing or wrong AHCI driver should not be the reason for not being able to get the OS installed.
Once Win7 is up and running, you can replace the generic MS AHCI driver by any other matching AHCI driver (even by a mod+signed one after having imported the Certificate).
then what could ahcix64s.sys (or disk.sys) issue mean?
This message has nothing to do with the driver you have asked me to modify. This was an Intel AHCI driver, whereas the file named ahcix64s.sys is an AMD AHCI driver.
I have no idea why you have tried to install an AMD AHCI driver, because your machine obviously has an Intel chipset.
Since an AMD AHCI driver named ahcix64.sys is neither within the original MS Win7 Image nor usable with your system, I suspect, that you haven’t used a clean Win7 ISO as source.
Regarding the A5 error I recommend to ask the acpi.sys patch experts.