Windows 11 keeps a friendly eye on your security settings, and sooner or later it points at Memory Integrity, under Core Isolation, and suggests you turn it on. On a newer PC you flip the switch and forget about it. On an older one, you flip it and Windows pushes back: it will not enable, because a driver already on your system is not compatible. Now you are staring at a warning about a device driver you have never thought about, unsure whether to hunt it down, ignore the whole thing, or worry. Here is what Memory Integrity does, why older PCs get blocked, and the questions worth asking before you enable it.
A note on the numbers: there is no public scoreboard of which drivers block Memory Integrity on how many machines, so this describes the common patterns rather than precise figures.
Key points at a glance
- What it is: Memory Integrity, also called Hypervisor-protected Code Integrity or HVCI, runs driver code-integrity checks inside an isolated, virtualized environment to make it harder for malware to hijack your PC through low-level drivers.
- Why older PCs get blocked: an old device driver that does not meet HVCI’s requirements is present, and Windows will not turn Memory Integrity on while it is installed.
- What tends to get flagged: old drivers for printers, audio, graphics, network adapters, and peripherals, or leftover drivers from software you no longer use.
- How to see the culprit: Windows Security shows a “Review incompatible drivers” list under Core Isolation that names the blocking driver.
- The fix: update the driver to a compatible version, remove the device or app that installed it, then enable Memory Integrity, or knowingly leave it off if you must keep the device.
Table of Contents
What Memory Integrity actually does
Memory Integrity is a security feature that guards the most sensitive part of Windows, the kernel, against being hijacked through low-level drivers. It works by using hardware virtualization to create an isolated environment where the checks that verify driver code cannot be tampered with, even by malware that has gained a foothold. In plain terms, it is a locked booth that inspects every kernel-mode driver before it is allowed to run, and blocks anything that does not pass. Microsoft’s guide to device security in the Windows Security app describes how it works. Because it inspects drivers so strictly, a driver that does not meet its standard is exactly what stops it from turning on.
Why older PCs often can’t turn it on
The reason older machines get blocked is accumulation. Over years of use, a PC picks up drivers from every printer, webcam, audio interface, graphics card, network adapter, and utility it has ever met, and some of those drivers predate HVCI’s requirements or were simply never updated to meet them. Memory Integrity will not enable while an incompatible driver is installed, because doing so would defeat the protection, so Windows refuses and tells you a device driver is the problem. This is not a sign your PC is broken; it is the feature doing its job. Newer PCs tend to ship with compatible drivers throughout, which is why the switch just works on them and stalls on an older, well-traveled system.
What commonly gets flagged
The blocking drivers fall into recognizable groups, even without exact counts. Old drivers for printers, scanners, and all-in-one devices are frequent offenders, as are legacy audio drivers, older graphics drivers, and network or wireless adapter drivers that have not been refreshed. Just as often, the culprit is a leftover: a driver installed by software you no longer use, an old utility, a virtual device, or a tool that never fully uninstalled. Some filter drivers from older security or connectivity software also get caught. The common thread is age and neglect rather than any single vendor, which is why the fix usually starts with identifying the specific driver rather than guessing.
How to check which driver is blocking it
You do not have to guess, because Windows names the driver for you. Open Windows Security, go to Device Security, and open the Core Isolation details, where, if Memory Integrity cannot turn on, you will find a “Review incompatible drivers” option that lists the offending driver by its file name and publisher. Write down what it shows, since the file name and publisher tell you which device or piece of software the driver belongs to, and that is what points you to a fix. This list is the single most useful step, because it turns a vague warning into a specific target you can update or remove.
The questions to ask before you enable it on an older PC
Before you start flipping switches on an older machine, a few questions save time and frustration. Does the incompatible-drivers list actually show anything, and if so, what device or software does each entry belong to? Can you get an updated, compatible driver, either from the device maker’s site or through Windows Update, or has that maker stopped supporting the device? Is the device or app still something you use, or can you simply remove it and its driver? Will there be a noticeable performance cost, since the virtualization Memory Integrity relies on can add overhead on older hardware? And, honestly, do you need HVCI for how you use this PC, or is the security trade-off of leaving it off acceptable for now? Answering these tells you whether enabling it is a quick win or more trouble than it is worth on that particular machine.
How to fix a blocking driver
Once you know the driver, the fixes are straightforward. First, try to update it: check the device maker’s website for a current driver, and check Windows Update, since a compatible version often exists. If the driver belongs to a device or program you no longer use, uninstall that device or app so its driver leaves with it, which is frequently the cleanest route. After updating or removing the blocker, return to Core Isolation and turn Memory Integrity on. If the only compatible driver does not exist and you cannot give up the device, you are left choosing between the device and the feature, and it is reasonable to leave Memory Integrity off with that trade-off understood. For unrelated Windows headaches while you are in there, our guide to fixing Windows 11 update errors may help.
How we compiled these figures
This overview draws on Microsoft’s documentation of Memory Integrity and Core Isolation, the way HVCI evaluates drivers, and the patterns that recur in real reports of blocked enablement. Because Microsoft does not publish statistics on which drivers block Memory Integrity across how many PCs, we described the common categories of offending drivers and the reliable diagnostic path rather than assigning percentages, and we weighted the guidance toward what actually gets people unstuck, chiefly identifying the specific driver and deciding whether to update it, remove it, or accept the trade-off.
This article is general information. Windows features, menu paths, and driver requirements change over time, so confirm the current steps in Microsoft’s documentation, and back up your data and create a restore point before updating or removing drivers or changing security settings.
Frequently asked questions
Why won’t Memory Integrity turn on in Windows 11?
Almost always because an incompatible device driver is installed, and Memory Integrity refuses to enable while one is present, since allowing it would undermine the protection. Windows tells you a driver is the problem and offers a “Review incompatible drivers” list under Core Isolation that names it. Update that driver to a compatible version or remove the device or app it belongs to, then try enabling the feature again. Older PCs hit this more often because of accumulated old drivers.
How do I find which driver is blocking Memory Integrity?
Open Windows Security, go to Device Security, open Core Isolation details, and look for the “Review incompatible drivers” option, which lists the blocking driver by file name and publisher. That information tells you which device or software the driver belongs to, which is what you need to update or remove it. Noting the exact name is the key step, since it turns the generic warning into a specific target you can act on.
Is it safe to leave Memory Integrity off?
It reduces a layer of protection against certain driver-based attacks, so on balance having it on is safer, but leaving it off is a reasonable trade-off if the only thing blocking it is a driver for a device you genuinely need and cannot update. Many people run securely without it. Weigh how you use the PC, keep the rest of your security current, and revisit it if a compatible driver later becomes available so you can turn it on then.
Will Memory Integrity slow down an older PC?
It can add some overhead, because it relies on hardware virtualization to isolate its checks, and on older hardware that overhead is more noticeable than on newer machines. For most everyday use the impact is modest, but on a low-powered or aging PC, or in demanding workloads, it is worth testing. If you notice a real slowdown after enabling it, you can weigh the performance cost against the security benefit and decide what fits that machine.
Should I update or remove the incompatible driver?
Update it if the device is one you use and a compatible driver exists from the maker or through Windows Update, since that keeps your hardware working and lets you enable the feature. Remove it if the driver belongs to a device or program you no longer use, which clears the blocker cleanly. Choose based on whether you still need the device, and only consider leaving Memory Integrity off when you must keep a device that has no compatible driver.
The bottom line
Memory Integrity is a genuine security upgrade, but on an older Windows 11 PC it often will not turn on because an aging, incompatible driver is in the way, and that is the feature protecting you rather than a fault. The path forward is not to force it but to identify the driver through the “Review incompatible drivers” list, then update it, remove the device or app it came from, and enable the feature, or knowingly leave it off if you must keep a device with no compatible driver. Ask whether the driver can be updated, whether the device is still needed, and whether the performance trade-off suits the machine, and you will make the right call for that PC. For more on keeping your devices running smoothly, browse The Other Stream’s Tech section, and see our guide to fixing connectivity issues after an update.