Core Isolation turned off due to WDCSAM64_PREWIN8.SYS incompatibility

Question

I have been running Windows 11 successfully on my Microsoft Surface for some time now with no problems.

Within the last day or so, I all of a sudden got a notification that Core Isolation has been disabled due to an incompatible driver, WDCSAM64_PREWIN8.SYS.

From what I can see, this driver is related to Western Digital. However, I do not have any Western Digital devices attached to my Surface, nor have I recently added/installed anything from Western Digital.

I have tried searching for this driver but have come up empty.

Answer 1

1. Select the Startbutton and type “Core isolation”.
2. Select the Core Isolation system settings from the search results to open the Windows security app.

On the Core isolation page, you’ll find Memory integrity along with the toggle to turn it on

• If you receive a notification / message says that the memory integrity can't be turn on follow the below steps.

1. Try to scan and fix.
2. If it is not solved, please click on "Review any driver incompatibilities".

3.We can see a driver or more.

4. Please note the published name here is "oem46.inf"
5. Select the Start button and type “Device Manager" and follow as shown below.

6. Select the right driver from Device manager"oem46.inf" and right click and select remove driver.

Example :-

7. System needs to be restarted after removal of the driver.

Hopefully this will solve your issues no need to install any software for this.

Answer 2

Thank you,

Worked like a charm, no addition software to install.

"... for Win11

RIGHT click on the START button and select WINDOWS TERMINAL (ADMIN)

Just Uninstall the driver usingpnputil /delete-driver oem<XX>.inf ..."

mine was oem35 (as determined by the internal incompatible drivers checker in Windows Security/Core isolation, but it is different for different devices..

Answer 3

I have tried this on my PC. It fails to delete the driver. I have even removed the Western Digital MyBook (external drive) and rebooted with no luck. I have attached the screen shot of the Core Isolation data and pnputil output.

Answer 4

Is there a space after the 49, that should not be there?

Is your internal 'Disk drive' as shown by device manager a WD hard drive ?

(although this may not matter, as an internal drive should have it's own oemxx.inf and not be depending on an obsolite driver-> system required/detected Microsoft drivers will generally be automaticly reinstalled by windows, if needed; except in some OEM/Manufacturer and/or user very customized computers). ****

If not, did you 'show hidden devices', and delete from Device Manager the external hard drive, before running the Windows Terminal command, after safely removing the external drive?

Note: my described device was an Asus with WDCSAM64_PREWIN8.SYS incompatibility .

Answer 5

Same thing with my Surface Pro 6. So far Microsoft customer service hasn't been able to resolve this.