Categories: Windows 11 & Windows 10Windows Server

SOLVED: Core Isolation Memory Integrity Incompatible Drivers WDCSAM64_PREWIN8.SYS

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: 1.2.0.0

Published name: oem26.inf

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

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.

View Comments

  • This worked for me. I did login as Administrator and followed the commands as shown in the example. My driver number was oem19.inf which I entered instead of the oem26.inf in the example. Problem solved...thank you!!

  • In my case it's says error deleting: "access denied". Can someone help?
    I tried all your instructions on PowerShell, even with command /force it says access denied.
    Thanks a lot!

  • I'm trying to delete a problem driver (lvbflt64.sys) on my pc. But the pnputil /enum-drivers command lists only the drivers ending in .inf

    • Dennis,
      The .inf file has information on how the driver is to be installed and will reference the .sys file (DLL). Just search for the base name of the driver (in your case lvbflt64 and you should find it in the list with a .INF suffix. This will be referenced as "Original Name". The OEMnnn.inf file will be shown associated with this and this is the driver to reference in the removal statement. At install time the original .INF file and the .SYS file are copied and windows names the original .INF file with a unique OEMnnn.INF name.

  • Perfect, thank you so much for this easy solution to an issue Microsoft should handle for its users, rather than leaving them stranded with a cryptic Windows Security error message and no help.

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Published by
Ian Matthews
3 years ago

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