Key Points
- Memory Integrity may fail due to the outdated pxhlpa64.sys driver. Identify and remove this incompatible driver to restore Windows 11 Core Isolation security.
- Fix pxhlpa64.sys by uninstalling legacy disc software, removing registry filter entries, deleting remaining DriverStore packages, and repairing system files to meet Windows 11 security standards.
- After removing all traces of pxhlpa64.sys, validate Memory Integrity through Windows Security to ensure full compliance with virtualization-based protections and resolve kernel-level driver conflicts.
Memory Integrity is part of Windows Core Isolation. It protects against kernel-level attacks by requiring drivers to meet security and compatibility standards. Some older drivers, such as pxhlpa64.sys, prevent the feature from turning on.
This article explains how to locate the incompatible driver, remove outdated components, repair related system entries, and confirm that Memory Integrity can be enabled safely.
Fixing the pxhlpa64.sys error when enabling memory integrity in Windows 11
Fixing the pxhlpa64.sys error involves finding the blocked driver, uninstalling software, removing filter driver entries, deleting the driver, repairing system integrity, and validating memory integrity.
📌 Prerequisites:
- Windows 11 with administrative privileges
- Access to Apps, Device Manager, and Windows Security
- Internet access for driver updates
- No third-party kernel filter drivers required for production workloads
Method 1: Find the blocked driver
This step identifies the driver blocking the feature.
📌 Use Case: This method is appropriate when Memory Integrity refuses to turn on or becomes disabled automatically after a reboot. It is also useful when verifying that pxhlpa64.sys is the actual cause of the issue.
Open Windows Security and navigate to Device Security. Afterward, access the Core Isolation Details page to see a list of drivers that don’t meet the requirements for Memory Integrity. If pxhlpa64.sys appears in the list, note its file path. This step ensures you have accurate information before cleanup.
Method 2: Uninstall software that installed pxhlpa64.sys
This step removes the software responsible for installing the filter driver.
📌 Use Case: This method is ideal when the system has a history of optical disc utilities, such as Roxio or Sonic, or when the computer came with OEM-provided media tools.
Through Windows Settings, access the list of installed applications and search for older disc-related utilities. Once located, uninstall them to eliminate their associated drivers. Restart your computer and return to the Core Isolation interface to verify if the driver is still visible.
Method 3: Remove filter driver entries from the registry
This step removes leftover registry entries to stop the system from referencing removed filters.
📌 Use Case: This method becomes necessary when Memory Integrity continues to report the presence of pxhlpa64.sys even after uninstalling all related software.
To remove filter entries, open the Registry Editor and navigate to the class definitions for storage devices. These class keys, usually labeled UpperFilters or LowerFilters, may reference pxhlpa64.sys.
Delete the entries that refer to this driver to prevent Windows from loading it in the future. Afterward, you’ll need to reboot the system.
Note that this step requires caution because unrelated filters must remain intact for other device functions to operate properly.
Method 4: Delete the driver from DriverStore
The Windows DriverStore may still have a copy of the driver package associated with pxhlpa64.sys.
📌 Use Case: This method applies when Memory Integrity still reports the presence of the driver despite other cleanup steps. It is especially relevant when the file exists in the DriverStore but is no longer present in the System32 directory.
Remove the driver from the DriverStore using the command-line driver utility, PNPUTIL. Enumerate the driver packages to identify the entry with pxhlpa64.sys. Once identified, delete the package and restart the system to ensure the driver cannot reload.
Method 5: Repair system integrity and update the chipset
This step ensures the operating system is in a clean and stable state by running system integrity checks and updating drivers.
📌 Use Case: This method is suitable when Windows continues to report driver issues after all targeted removal actions have been performed.
Run the System File Checker and DISM restoration commands to allow Windows to replace corrupted or missing system files. Afterward, update the chipset and storage drivers directly from the manufacturer’s or OEM’s support site. These ensure full compatibility with Windows 11’s security requirements.
Method 6: Validate memory integrity after cleanup
This step ensures the system meets Microsoft’s requirements for virtualization-based security.
📌 Use Case: This final method is used after performing any combination of driver removal, registry cleanup, or system repairs.
Validation involves returning to the Core Isolation Details page in Windows security and attempting to toggle Memory Integrity on. Windows will allow the feature to activate if the cleanup was successful. After the automatic reboot, review the same interface to see if any incompatible drivers are listed. This typically means the system is now compliant.
Troubleshooting common pxhlpa64.sys issues
The following are common pxhlpa64.sys issues and ways to resolve them:
Pxhlpa64.sys still appears after uninstalling the software
If pxhlpa64.sys still appears, remove registry filter entries and delete the driver manually.
Memory Integrity turns off after reboot
In this case, a different kernel driver may be incompatible. You’ll want to review the complete list again to identify the driver causing issues.
The system cannot delete the driver
If the system can’t delete the driver, use pnputil with the force parameter and verify that no active services depend on it.
New incompatible drivers appear
When this happens, install the latest chipset, storage, and OEM support packages.
The optical drive stops working
If the optical drive stops working, install updated vendor drivers without reinstalling older burning suites.
Resolving the pxhlpa64.sys issue
The pxhlpa64.sys driver is a filter component that blocks Memory Integrity on Windows 11. To prevent this, you’ll have to remove outdated disc utilities, clean filter entries, update drivers, and repair system components to ensure you can re-enable advanced security protections. A systematic approach ensures the feature activates without disrupting device functionality.
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