How to fix driver incompatibility with core isolation

You're unable to enable Core Isolation (Memory Integrity) in Windows Security because incompatible modem driver files are blocking it after a recent Windows 11 update.

To Troubleshoot

1. Identify the incompatible drivers — Go to Windows Security > Device Security > Core isolation details. Click Review incompatible drivers to see the specific driver files blocking Memory Integrity.
2. Check for updated drivers — Visit the modem manufacturer's website and download the latest HVCI-compatible driver version. Even if you have the latest version, the manufacturer may release an updated driver that supports Memory Integrity.
3. Update via Windows Update — Go to Settings > Windows Update > Advanced options > Optional updates and check if a newer driver is available through Windows Update.
4. Update via Device Manager — Open Device Manager, right-click the modem device, select Update driver > Search automatically for drivers to check for a newer compatible version.
5. Contact the manufacturer — If no compatible driver is available, contact the modem manufacturer and request an HVCI-compatible driver. Explain that Windows 11 requires drivers to be compatible with Memory Integrity (Hypervisor-protected Code Integrity).
6. Evaluate the trade-off — If a compatible driver is not yet available, you have two options:
   1. Keep the modem installed and leave Memory Integrity off until the manufacturer provides an update
7. Remove the modem driver/software if the device is not critical, which will allow you to enable Memory Integrity Note: Forcing Memory Integrity on while incompatible drivers are present is not supported and may cause system instability or blue screens.

Reference

• Enable virtualization-based protection of code integrity
• Device security in the Windows Security app