Encountering issues related to ftdibus.sys and Memory Integrity in Windows can be a frustrating experience, especially when you’re trying to keep your system secure with built-in core isolation features. The driver ftdibus.sys is associated with FTDI (Future Technology Devices International) USB-to-serial converters, a crucial component for many developers, engineers, and users who employ legacy hardware. If this driver conflicts with Windows’ Memory Integrity, it can trigger critical system warnings or prevent the activation of advanced security features.
TLDR: Fixing ftdibus.sys and Memory Integrity Conflicts
If Windows warns you about issues with ftdibus.sys when trying to enable Memory Integrity in Core Isolation, it’s most likely due to a signed driver compatibility problem. The safest approach is to install the latest certified FTDI drivers from the official source. If that does not help, manually removing the problematic driver version and allowing Windows to handle automatic driver management often resolves the issue. Always ensure to backup critical files and check hardware compatibility before making major driver changes.
Understanding the Problem
Windows 10 and Windows 11 include a feature known as Memory Integrity under the Core Isolation security settings. This feature uses virtualization-based security (VBS) to prevent malicious code from accessing high-security processes. However, older or poorly signed drivers can conflict with this feature, and ftdibus.sys is a common culprit.
When this happens, you may see an error like:
“Memory Integrity can’t be turned on. Try resolving any incompatibilities with your drivers.”
This message usually includes a note referencing ftdibus.sys, signaling it’s incompatible with the secure driver signing required by Windows Memory Integrity.
Step-by-Step Guide: Fixing the ftdibus.sys Memory Integrity Issue
Step 1: Verify the Incompatible Driver
Before making any changes, confirm that ftdibus.sys is indeed the problematic driver.
- Open the Start Menu and search for Core Isolation.
- Select Core Isolation > Memory Integrity.
- If it’s turned off due to incompatible drivers, click Review Incompatible Drivers.
- Check if ftdibus.sys is listed. If found, proceed with the following steps.
Step 2: Download the Latest FTDI Driver
The issue may be caused by an outdated or unofficial version of the driver. Updating to the latest version often resolves the compatibility issue.
- Visit the official FTDI driver download page: FTDI VCP Drivers.
- Identify the appropriate driver for your Windows version and system architecture (32-bit or 64-bit).
- Download the certified and WHQL-signed version.
- Install the driver following FTDI’s instructions, and restart the system afterward.
After restarting, return to the Core Isolation settings and check if the Memory Integrity option is now available.
Step 3: Uninstall the Problematic Driver Version
If installing the latest driver doesn’t solve the issue, you may need to manually remove the incompatible or unsigned version of ftdibus.sys.
- Open Device Manager (search in the Start Menu).
- Look under Universal Serial Bus controllers or Ports (COM & LPT) for FTDI-related entries.
- Right-click the device (e.g., “USB Serial Converter”) and select Uninstall device.
- Check the box that says Delete the driver software for this device and confirm.
After uninstalling, remove any remaining traces manually:
- Press Win + R, type cmd, right-click and run as Administrator.
- Enter the following command to list all instances of the driver:
- Use the published name to delete each instance:
- Replace oemXX.inf with the actual file names found.
pnputil /enum-drivers | findstr ftdibus.sys
pnputil /delete-driver oemXX.inf /uninstall /force
Step 4: Reboot and Recheck
Restart your PC. Once you’re back into the system, revisit the Core Isolation settings:
- Type Core Isolation in the search bar.
- Ensure that Memory Integrity can now be enabled.
If successful, the warning about ftdibus.sys should no longer appear.
Optional: Use Compatibility Checking Tools
To ensure system compatibility with Memory Integrity and identify all offending drivers, you can use third-party utilities or Microsoft’s own tools:
- Download and install Microsoft Sysinternals Sigcheck.
- Run it from an elevated Command Prompt:
- Review the results for ftdibus.sys and check the digital signature status.
sigcheck -q -w -e -s C:\Windows\System32\drivers
Preventative Steps for the Future
Once the issue is resolved, consider the following steps to avoid similar issues in the future:
- Enable Automatic Driver Updates: Windows Update will often deliver the latest signed versions when left to manage compatible hardware.
- Register for FTDI’s Update Notices: If you frequently use FTDI devices, stay informed about new driver releases.
- Backup Drivers: If you find a configuration that works, make a backup using third-party tools or Windows System Image Backup.
When to Seek Professional Help
If your use case involves production environments or mission-critical systems, and you’re facing persistent Memory Integrity compatibility issues, it may be safer to:
- Contact FTDI support directly and provide driver version details.
- Reach out to an IT administrator or technician who can handle legacy drivers without compromising system security.
Never disable Memory Integrity unless absolutely necessary, especially if working in sensitive environments.
Conclusion
Resolving the ftdibus.sys Memory Integrity conflict may seem complex at first, but it’s often a matter of proper driver management. By identifying the problem, updating or removing the driver, and testing Integrity settings, you can maintain both hardware functionality and system security.
As Windows continues to evolve with stricter hardware and driver validation protocols, staying current with signed and certified drivers becomes increasingly important. Don’t ignore warnings from the Core Isolation subsystem; instead, fix them responsibly for a more secure and stable computing experience.
