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

  • Very thanks, I found a lot of methods to solve this problem but didn't work. U gave a useful method.

  • i have 26oem.inf like hw_usbdev.info or Huawei incorporated, i don´t found the driver WDCSAM64_PREWIN8.SYS.

  • Thank you! It was very useful. I had the same problem as in another comment, receiving the "access denied" message while trying to delete the file. That's strange because I'm the owner of the laptop and am supposed to be the administrator. But tried executing the windows terminal as administrator and could delete the file. In Windows 11, before executing the terminal, choose the option as administrator.

  • thanks Ian Matthews. I've been trying to phrase my search phrase just right to find this information for 24 hours! I finally achieved! thank you much for this info.

  • Thank you Ian. Your instructions were very good, and I was able to remove the old, no longer needed, driver.

  • Thank you very much. I had a different incompatible driver (AsIO64.sys, oem45.inf) but the same problem. I tried so many things without success before I tried your technique. Your solution worked perfectly.

  • I deleted every driver that was unnecessary and listed there. After deleting & scanning there are no incompatible drivers, but still I can't turn on Memory Integrity.

    • Hi Robert, we responded to your previous comment with the same suggestions we would make here:

      Hi Robert;

      Three things to try:
      1: reboot
      2: reboot in safe mode
      3: uninstall any programs / addins you are not using - many people leave software intalled for old scanners, printers, cameras... and that really expands your attack surface

      Let us know how that goes and thanks for checking in with us.

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Published by
Ian Matthews
3 years ago

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