If you are trying to tighten up your security by adding Virtualization-Based Security (aka VBS) to your Windows 11 you might find this error:

Core Isolation  Memory Integrity
Incompatible Drivers WDCSAM64_PREWIN8.SYS

Driver date: 11/29/2017
Driver version:

Published name: oem26.inf

Windows 11 Core Issolation incompatible driver wdcsam64_prewin8 sys

This is an old driver that ships with both Windows 10 and Windows 11 and very few people need it.  In fact we have never run into a situation of any machine using WDCSAM64_PREWIN8.SYS .

Fortunately, it is very easy to remove:

  1. RIGHT click on the START button and select WINDOWS TERMINAL (ADMIN)
    • If you are on Windows 10, select POWERSHELL (ADMIN)
  2. You can then list all of the drivers on your computer using pnputil /enum-drivers and find the one with WDCSAM64_PREWIN8.SYS or you can just look at the error message.  In my case the driver that needs to go is OEM26.INF
  3. Uninstall the driver using pnputil /delete-driver oem<XX>.inf

2 Windows 11 Core Issolation uninstall - remove incompatible driver wdcsam64_prewin8 sys

You do NOT need a reboot so you can immediately retry to enable CORE ISOLATION and you should see a prompt to reboot once Core Isolation > Memory Integrity is turned ON.

Windows 11 Core Issolation Reboot Required


k · September 17, 2022 at 8:21 am

Thank you!! I used cmd as habit then later realized had to use terminal. Now it is all resolved

Ken J · September 16, 2022 at 8:48 am

I tried this to remove rcblan.sys, and I got the message, “failed to delete driver package: The system cannot find the path specified.” Help appreciated.

Dim With · September 14, 2022 at 9:37 am

Thanks, it’s working

Bart · September 14, 2022 at 7:47 am

Using /force as described by Robert Hadley 9/7/2022 removed the driver when “one or more devices are presently installed using the specified INF.” No adverse effects except that the new Memory Integrity setting blocked a Gigabyte driver.

jennifer · September 9, 2022 at 11:25 am

re: Core Isolation Memory Integrity
Incompatible Drivers WDCSAM64_PREWIN8.SYS

got this error –
Failed to delete driver package: One or more devices are presently installed using the specified INF.

Alan · September 8, 2022 at 6:41 am

I went through the procedures to delete the files shown as incompatible. However, when I entered the OEM file to delete it, it said it failed and that access was denied. Is this because my laptop is a company laptop, and they may not allow me to delete these things? Any ideas?

    rr · September 17, 2022 at 7:45 pm

    run as admin

Robert Hadley · September 7, 2022 at 3:24 pm

found elsewhere, when adding the command pnputil /delete-driver oem.inf, if it doesn’t work, change it to pnputil /delete-driver oem.inf /force it got rid of the pesky drivers that would not go away.

    John · September 14, 2022 at 8:40 pm

    Perfect answer! Thank you!!!

Cris · September 7, 2022 at 4:07 am

Thanks, it worked!

P DeLillo · September 6, 2022 at 11:49 am

The file won’t uninstall as directed. It says one or more devices installed are using the specified INF. The original culprit drive has been physically removed and uninstalled on device manager. My Passport backup drive is disconnected and also uninstalled on device manager. Several restarts, including safe mode. No change. Help.

    Monty · September 14, 2022 at 1:28 pm

    For those of you who get message that can’t be deleted because it is needed by one or more devices, see note above…

    Simply add /force to the end of the original command forces it to get deleted. Should look something like this:
    “pnputil /delete-driver oem.inf /force”
    (credit: Robert Hadley above)

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