How to fix
Memory integrity not running due to STTub30.sys (STmicroelectronics) incompatible driver
on Windows

Hello, I have received a message that Core Isolation has an incompatible driver, STTub30.sys (STmicroelectronics), due to which Memory Integrity was disabled. I have installed the latest Windows updates, but I still receive the message. Any ideas on how to fix this? Thanks in advance.

Core Isolation and Memory Integrity are relatively new iterations of Microsoft Defender, the built-in antivirus that can be found in all recent Windows versions. Unfortunately, some users found that they couldn't turn on Memory Integrity because Windows found an incompatible driver, STTub30.sys (STmicroelectronics) on their devices. This can be a huge problem, as Defender is not running at its full capacity.

Since malware has been evolving rapidly in the past decade or so, threats like ransomware[ref en-1] are running rampant, and hundreds of users get infected every day. While some users prefer to use third-party security software, those who opt for Windows' built-in security tool are also protected very well, as long as it is running properly. That being said, when Memory Integrity is turned off, it is no longer the case, so it becomes vital to fix STTub30.sys (STmicroelectronics) incompatible driver issues on the system.

Some users reported the prompt telling that Memory Integrity was turned off seemingly out of the blue, while others claimed issues started after updating or reinstalling drivers, updating Windows, or performing other tasks. Other people claimed that several other issues, such as Firewall not working due to STTub30.sys, also occurred.

The reason for Core isolation and Memory Integrity to be turned off are the incompatible or corrupt driver. In this case, STmicroelectronics is a Switzerland-based semiconductor developer and producer. The component in question is a Kernel[ref en-2] device driver with the product name Generic STM USB Driver.[ref en-3]

Before you proceed with the solutions below, make sure that your Windows is running on the latest version and is up-to-date. Also, if your system files are corrupted, it may also cause the device to malfunction, so we recommend first running a scan with a PC repair tool [d1].

Fix 1. Get rid of the driver using the elevated Command Prompt

Some users managed to fix the Core Isolation issue by removing the driver altogether. To do so, proceed with the following steps:

• Type in cmd in Windows search
• Right-click on Command Prompt and select Run as administrator
• When User Account Control pop-up shows up, click Yes
• Now, copy and paste the following command link, pressing Enter afterward:
  dism /online /get-drivers /format:table

• Your next task is to find the line containing the STmicroelectronics under Provider Name, then take note of the Published name
• Next, type in the following command, replacing "Published name" with the driver name, for example:
  pnputil /delete-driver oem33.inf  /uninstall /force
• Press Enter
• Restart your system.

Fix 2. Replace the STTub30.sys file

One of the ways users managed to fix the problem was by replacing the file that was causing the problem - STTub30.sys. To get the newest version, however, you'll have to download it from the GitHub platform, which is by no means official (the developer does not have this version of the driver published on its official website, although this may change in the future). Nonetheless, Virus Total checks confirm the file is safe to use.

• Go to the C:\Windows\System32\drivers\ location and find STTub30.sys file. Copy it to another location for a backup (you can use USB or cloud services too)
• Download the newest file version from the GitHub site
• Now, go back to C:\Windows\System32\drivers\ and copy the new file you downloaded into this location

• You will be asked to grand Administrator permissions - do so
• Reboot your system
• After a restart, go to Windows Security > Device Security > Core Isolation and enable Memory integrity.