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

I have the same exact issue but on a Dell XPS 7590. Same drive name.

Answer 3

Did your error message just pop up recently as well? Perhaps it is due to some recent Windows update?

Answer 4

i have the same problem and my WD hdd stopped working the other day. Using AORUS 17G YD.

Answer 5

Hi Carol,

I am not sure how you deleted oem46.inf or how you found it. And I am not a Microsoft support expert. But I DID finally solve the problem with help from a helptul person named Ramesh on this site. If you are comfortable working in Powershell/ Admin Command Prompts, it is required to fix the problem. If not, you should find a friend who is.

There are two things to know. First, I never could find the file we both were told is the problem: wdcsam64_prewin8.sys. The file(s) that actually must be removed are named wdcsam from Western Digital. Second, they are indeed oemxx.inf (xx can be one or two digit number). I actually found 2 of them: oem0 and oem99.inf. Removing both properly fixed the problem. Note the word "properly". Your computer assigned the xx number itself. So, not necessarily 46 or 0 or 99!

If you are ok working in Powershell, as Admin, open the Command Line prompt and type after C:\Windows\System32>

pnputil /enum drivers (note the spaces before / and drivers) and then hit enter.

Then you should get a long list of all drivers in .inf and find the one (or in my case 2) from WD. Note carefully the number(s)

Then on the Command line, after the prompt as above, type

pnputil /delete-driver oemxx.inf (note the spaces before / and oem and enter the number you found in place of xx) and hit enter.

You should get a comment that the driver was deleted.

This should fix it.

Best of luck. Thanks to Ramesh, not me.