Upgrade to Win11 on an Intel X99 Chipset fails due to a "wrong" Intel Raid driver


I have a Dell Precision Tower 5810 with Intel Xeon CPU E5-1620 v3 processors running Windows 10 64 bits latest release. This computer has a C600/C600+/C220 Series Chipset X99 controller., and I have three SATA disks connected there: one SATA SSD for OS and APPS and two additional SATA disks in a RAID 1 configuration. Initially I was having Dell recommended Intel RSTe Drivers (it was version 3.6 or 3.5 I don’t remember exactly) but with the two different controllers: Intel SATA AHCI and Intel SATA RAID present in the system.

Despite that I know that the processor is not officially supported by Windows 11, I use t AllowUpgradesWithUnsupportedTPMOrCPU Microsoft Official hack for circumventing this requirement and the iupgrade goes smoothly till the 1st OS boot, during this first boot Windows 11 shows a BSOD complaining about IaStorA.sys driver, then it rolls back the OS installation to the original windows 10.

I have updated my drivers to the latest versions available in these forums for each platform (v.4.x, v.5.x, v6.x, v.7.x) ; I have also reconfigured my system to use Standard MS drivers for AHCI and the Intel specific ones for RAID controller, but the result is always the same BSOD because of IAstorX.sys driver and rollback of the upgrade. I’m currently running version of the drivers.

Any idea about this issue?. Has anyone been able to upgrade to Windows 11 using a similar config with X99 controller?
Thanks in advance for the support and help

Edit by Fernando: Thread moved into the Win11 Sub-Forum (due to the specific Win11 problem) and thread title customized


@JuanLUX : Welcome to the Win-RAID Forum!
Please post the HardwareIDs of both Intel SATA Controllers (AHCI and RAID). You get them by doing a right-click onto them and then choosing the options "Properties" > "Details" > "Property" > "HardwareIDs".
Maybe you will have to use an Intel RST RAID driver (and not an RSTe one).
Enjoy the Forum and good luck!
Dieter (alias Fernando

Thanks Fernando (Dieter) for the warm welcome and for moving the thread to the appropriate subforum, below you will find the PCI Vendor & Device IDs for either the RAID and the AHCI controllers:

Intel(R) c600+/C220+ series chipset SATA RAID Controller

Standard SATA AHCI Controller

In regards to your suggestion of using RST and not RSTe correct me if I’m wrong but with X99 chipset is only possible to use the RSTe as the classical drivers are not suitable for it. Am I missing anything?

Depending on modules used in bios:

For bios from https://dl.dell.com/FOLDER06708149M/1/T5…fn=T5810A34.exe
1 - Disk Controller
EFI Intel RSTe for SATA -
OROM Intel RSTe for SATA -
EFI NVMe Driver present

@JuanLUX :
lfb6 is right - the option for owners of an X99 chipset RAID system to use an Intel RST RAID driver instead of an RSTe one, depends on the mainboard manufacturer and the specific BIOS configuration.
The big majority of X99 chipset mainboards have a split solution: The on-board SATA ports are supported by RST drivers, whereas the sSATA ports (mainly running only in AHCI mode) need RSTe drivers.
I don’t know the exact reason why the upgrade from Win10 to Win11 failed in your case, but I suspect a mismatch between the Win11 in-box Intel RST RAID driver v15.44.0.1015 and the Intel RSTe driver v7.6.0.1020, which is in-use while running Win10.
Since the Intel RSTe RAID driver, which obviously caused the interruption of the OS upgrade, is dispensable for this procedure (your drive C is managed by the MS in-box AHCI driver), I recommend to do the following:
1. Make a backup of your current used drive C: (with the OS and the hidden boot partition).
2. Unplug the power cables from your 2 RAID1 array member disks.
3. Re-try to upgrade to Win11.
4. Once Win11 is up (inclusive all available Updates) and running fine, reconnect the power cables of the 2 RAID1 array member disks, power on your PC and report here what happens (in case of a BSOD unplug the RAID1 array members and power on the PC again).
Good luck!

Thanks lfb6 and Fernando for your messages.

@lfb6 I confirm that I’m on latest BIOS version (A34) and also with OROM RSTe (see screenshots below)


Regarding BIOS options for the system are also very limited as you can see in the screenshot:


@Fernando :

I will follow your suggestion and during the weekend I will clone my boot drive with win10 and disconnect the RAID1 disks to perform the upgrade to Win11. I will report back the results.

Thanks again for you help and support.


Were those BSODs always iaStorA.sys? From RSTe 5.x it should be iaStorE.sys?

Did you clean up your installed drivers with pnputil before starting the upgrade process?

Do you have the possibility to try a fresh Win11 install on another harddisk, raid disks disconnected?

@JuanLUX :

Yes, the iaStorA.sys error message indicates, that there is still an old v4 platform RSTe RAID driver named iaStorA.sys in the Windows “Driver” store. Since the Intel RAID EFI SataDriver of your BIOS is still v4.6.0.1018 and doesn’t match at all the currently installed RSTe v7 platform RAID driver, it seems possible for me, that the Win11 Setup tried to install a v4 platform Intel RAID driver, but didn’t succeed.
In this case there are 2 options:
a) update the Intel EFI “RaidDriver” module of the BIOS (requires a BIOS mod and flashing such mod BIOS) or
b) downgrade the Intel RSTe RAID storage driver to a v4 platform one.

@lfb6 Sorry I explained incorrectly in my first post, yes wiith versions 3.x and 4.x it was iaStorA.sys the one giving the 0xC19000101, 0x20017 BSOD error

Starting with RSTe 5.x it was iaStorE.sys

I didn’t perform any cleanup with pnputil, it was only when I switch the AHCI SATA controller to Windows standard when I uninstall the iaStorA.sys driver

Currently in the drivers directory I have the following iaStor?.* drivers with their versions:


I’m awaiting for a new disk to arrive on Friday to do a fresh Win11 install on it without the Raid disks


v4.6.0.1018 was the latest official update that I found in Dell site either for the controller BIOS and for the drivers, and the error during Win11 upgrade was the same when both versions matched
Not sure if there is a trustful Mod bios for my controller

I revert back to v4.6.0.1018 some days ago and it doesn’t solve the issue

As commented I’m awaiting for a new disk that I ordered just for doing more tests during weekend.

I’m thinking also on doing a fresh Win11 install NVME disk mounted on a PCIe adapter without any other disk attached to the system and after that connect the two RAID disks

@JuanLUX : Thanks for your additional report.

You should never uninstall a storage driver, when you are going to update or replace it. Reason: The OS needs the information to be able to revert to the previously used properly working driver.

The mainboard manufacturers do not test and offer the latest available drivers for their old hardware. If you want to get the latest Intel RST/RSTe drivers and RAID modules, you should better look into this Forum.

I needed to do thatfrom device manager in order to allow the system to use the Standard AHCI driver

Is there any text for the BSOD error 0xC91…like ‘unaccessible boot device’ ot any other text? Could you post a picture of this BSOD?

If one searches for this error there’s a lot of finds, doesn’t seem to be very specific (and there’s no specific solution either).

In addition to an earlier post: RST or RSTe mode isn’t only the modules, it’s chipset configuration, too. SATA controller changes device ID when configured as RST, RSTe, AHCI , see https://www.intel.com/content/dam/www/pu…h-datasheet.pdf

I wonder why you’d have 2 different drivers loading here. I have a C222 board with RSTe, and there’s no SATA driver for my (of course) non-RAID CD drive?


>Here< is a guide about how to switch to a previously used other AHCI driver (here to return to the generic MS in-box AHCI driver) without deleting the currently used specific AHCI drriver.