BrUsbSib.sys Causes Memory Integrity Issue in Windows 11

Published by Nyau Wai Hoe - Updated on

BrUsbSib.sys, a driver developed by Brother Industries Ltd., has been found to cause incompatible drivers issues with certain Windows 11 features, particularly with the memory integrity option under core isolation in Windows Security’s Device Security. This issue prevents the enabling of the memory integrity option, hence compromising your system’s potential security features. This article aims to provide a step-by-step solution for this problem.

Also see: Memory Integrity Can’t Be Turned On (Windows 11)

BrUsbSib.sys Incompatible Drivers in Windows 11

Removing the BrUsbSib.sys Brother driver

The primary solution to this issue involves using the pnputil command-line tool, included in Windows, to forcibly uninstall the problematic driver. Specifically, you’d use the command pnputil /delete-driver oemxx.inf /uninstall /force where oemxx.inf represents the driver file for BrUsbSib.sys.

However, it’s important to understand that the specific oemxx.inf driver name may vary from one system to another. Therefore, it’s not guaranteed that the oemxx.inf name referenced in various guides, such as oem21.inf, would necessarily apply to your system. The oemxx.inf file associated with BrUsbSib.sys on your computer may be different. As such, you need to accurately identify the oemxx.inf driver file specific to your system before executing the uninstallation command.

Related resource: How to Uninstall Drivers in Windows 11

BrUsbSib.sys Memory Integrity in Windows 11

Understanding OEM INF Files in Windows

A file like “oem21.inf” is typically referred to as an OEM (Original Equipment Manufacturer) INF file. INF stands for “information” or “installer” file, and it is a plain text file that contains instructions and configuration data for installing and configuring a particular device driver or software component on the Windows operating system.

OEM INF files are provided by hardware manufacturers or OEMs to accompany their hardware devices. These files contain information about the device, such as its hardware ID, driver version, manufacturer details, and other necessary configurations.

Where are OEM INF files located in Windows 11

When you connect a hardware device to your computer, Windows uses the INF file associated with that device to identify and install the appropriate driver. The INF file specifies how the driver should be installed, including any additional files that may be required.

In the case of “oem21.inf,” the number “21” is typically a unique identifier assigned by Windows to distinguish between different OEM INF files. The actual file name may vary depending on the device manufacturer and the driver version.

Useful tip: How to See What Drivers Are Installed in Windows 11

Step 1: Identifying the BrUsbSib.sys driver name

Before proceeding with the uninstallation process, you’ll need to find the specific oemxx.inf file associated with the problematic BrUsbSib.sys driver. Here are two ways you can accomplish this:

Checking the BrUsbSib.sys Incompatible drivers section

The first method involves checking the information provided directly by the incompatible drivers section where the error occurs:

  1. Navigate to the “Incompatible drivers” section where the error message relating to BrUsbSib.sys is displayed.
  2. Check for the “Publisher name” listed under BrUsbSib.sys. This name corresponds to the oemxx.inf file you need to delete. For example, in the sample screenshot provided below, the oemxx.inf file was oem46.inf.Remove BrUsbSib.sys Brother Driver

Using pnputil command

The second method requires the use of the pnputil command:

  1. Launch the command prompt in administrator mode. Press the Windows key, type “Command Prompt“, right-click on it and choose “Run as administrator“.Command Prompt Run as Administrator
  2. Once the command prompt window opens, type pnputil /enum-drivers and press Enter.pnputil enum-drivers to list all drivers in Windows
  3. A comprehensive list of drivers installed on your system will be displayed. From this list, search for an entry that is linked to Brother Industries or directly references BrUsbSib.sys.

Linked issue: Can’t Completely Uninstall a Driver in Windows 11 (Fix)

Step 2: Deleting the BrUsbSib.sys driver in Windows 11

After pinpointing the problematic driver, proceed to uninstall it using the following steps:

  1. Re-open the command prompt window in administrator mode.
  2. Type the command pnputil /delete-driver oemxx.inf /uninstall /force, replacing oemxx.inf with the specific oemxx.inf driver file name you identified earlier. In my case, it was oem46.inf.How to delete and uninstall BrUsbSib.sys Brother Driver
  3. Hit Enter to execute the command. This action will uninstall the problematic driver.
  4. Upon successful uninstallation, reboot your system to apply the changes.

Related guide: Using a PowerShell Script to Add a Printer Driver by IP

Verifying if the Memory Integrity option can be turned on

After your system has restarted, validate the success of the process by trying to enable the Memory Integrity option again:

  1. Click the “Start” button, and select “Settings“.
  2. Inside “Settings“, navigate to “Privacy & Security“.Open Windows Security from Settings
  3. From there, click on “Windows Security“, followed by “Device Security“.
  4. Under the “Core Isolation”, click on “Core isolation details“.Windows 11 Core isolation details
  5. Attempt to toggle on the “Memory Integrity” option.Turn on Memory Integrity BrUsbSib.sys

If the enabling process completes without throwing any errors, it’s a good indicator that the incompatible driver issue has been effectively resolved.

BrUsbSib.sys driver update and download

While the BrUsbSib.sys driver might cause some issues with Windows 11’s security features, it is still a necessary component for the smooth operation of Brother Industries’ devices, such as printers, connected to your system. If you have removed this driver but still need to use your Brother device, you might need to download and install an updated version of the driver. Here’s how you can do it:

Downloading the latest driver from the official Brother website

Brother Industries Ltd. routinely updates their drivers to ensure compatibility with the latest operating systems and to fix any known issues. Here are the steps to download the latest driver:

  1. Visit the official Brother Industries Ltd. website.
  2. Navigate to the “Support” section, and then click on “Software and Driver Downloads“.BrUsbSib.sys driver update
  3. In the search box, type your product model, then press Enter or click the search icon.BrUsbSib.sys download
  4. In the results, find the correct model and click on the “Downloads” button.
  5. Select your operating system (in this case, “Windows 11“) from the drop-down menu.
  6. Click on “Search“, and a list of available drivers for your product and OS will be displayed.
  7. Click “Download” beside the driver that suits your hardware and follow the on-screen instructions to install it.

Using Windows Update to automatically update the Brother driver

If you prefer, you can also use Windows Update to automatically update your drivers, including the BrUsbSib.sys driver. This is especially helpful as Microsoft maintains a comprehensive repository of drivers. Here’s how:

  1. Connect your Brother device to your computer.
  2. Click the “Start” button, then select “Settings“.
  3. Click on “Windows Update”, then click “Check for updates“.Check for Windows Update
  4. If there are any updates for your Brother device, they will be listed under the “Optional updates” section.Optional updates graphics driver Windows 11
  5. Click “Download and install” to update the driver.

With either of these methods, you should be able to restore functionality to your Brother device while maintaining the security features of Windows 11. Remember to keep your drivers up-to-date to ensure compatibility and smooth operation of your hardware and software.


Troublesome as they may be, driver incompatibility issues like those caused by BrUsbSib.sys are solvable with a methodical approach. The process of identifying the problematic “oemxx.inf” driver and uninstalling it might seem challenging, especially due to system variations. However, the payoff in terms of security enhancements makes the effort worthwhile.

The memory integrity feature in core isolation provides a robust defense against code injection attacks by isolating system processes from potential malware or other harmful software. Therefore, resolving any issues that prevent its enabling is a valuable step towards strengthening your system’s security.

A good maintenance tip is to regularly update your drivers to prevent future incompatibility issues. However, if you encounter any difficulties or uncertainties throughout this process, do not hesitate to seek professional help.

Nyau Wai Hoe
Nyau Wai Hoe is the Founder and Chief Editor of With a degree in software engineering and over 12 years of experience in the tech support industry, Nyau has established himself as an expert in the field, with a primary focus on the Microsoft Windows operating system. As a tech enthusiast, he loves exploring new technologies and leveraging them to solve real-life problems.

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