Recent Windows 11 updates can switch on Memory Integrity by themselves. Microsoft added this in the October 28, 2026 preview update (KB5127936), and the November 10 security update (KB5132061) brings the same change to 25H2 and 26H2 PCs that skipped the preview. To check it, open Windows Security > Device security > Core isolation details. If your games and devices work fine, leave it on.
What changed in Windows 11
The KB5127936 changelog says supported PCs "may now have memory integrity (HVCI) enabled during updates." Microsoft adds that it respects choices already made by you or your IT admin. So if you turned it off yourself before, Windows will not flip it back on.
Windows checks your hardware, driver compatibility and expected performance before it acts. The rollout is gradual, so your PC may not get it right away. On work PCs, Microsoft's Peter Waxman confirmed that "enterprise policy takes precedence over the automatic enablement."
What Memory Integrity actually does
Memory Integrity is also called hypervisor-protected code integrity, or HVCI. Normally the Windows kernel decides whether a driver is safe to run. If malware takes over the kernel, those checks can't be trusted anymore. Memory Integrity moves them into a small isolated space created by the Windows hypervisor, so a hacked kernel can't simply load unverified code.
It is a real security gain. It also has a cost, which is why some people want to know if it is on.
How to check Memory Integrity step by step
- Open Start and type Windows Security, then open it.
- Click Device security.
- Under Core isolation, click Core isolation details.
- Look at the Memory integrity toggle. On means the protection is active.
Advanced users can also run this in an admin PowerShell window: Get-CimInstance -ClassName Win32_DeviceGuard -Namespace root\Microsoft\Windows\DeviceGuard. If SecurityServicesRunning contains 2, memory integrity is running.
How to turn off Memory Integrity
- Go back to Core isolation details in Windows Security.
- Switch Memory integrity to Off.
- Restart the PC. The change only takes effect after a restart.
- Come back to the same page after the restart to confirm it stayed off.
You can switch it back on from the same screen at any time.
Should you turn it off?
Honestly, most people should not. I would only turn it off for a clear reason, like a game that refuses to start or a device driver that Windows blocks.
Microsoft's own documentation warns that some apps and drivers are incompatible with memory integrity, and in rare cases this can cause a blue screen. Its driver compatibility page lists "anti-cheat solutions with gaming" among the software that has had problems. If Windows tells you a driver can't load, first look for an updated driver from the manufacturer or Windows Update.
Performance is the other worry. Microsoft says memory integrity works better on Intel Kaby Lake and newer, and on AMD Zen 2 and newer, because older chips have to emulate key features. Tom's Hardware measured an average gaming drop of about 5% in 2021, and around 5% again in a 2023 retest, up to 10% in some games. That is noticeable in a benchmark. In daily use, most people will never feel it.
Quick answers
Why did Memory Integrity turn on by itself?
Because your PC installed KB5127936 or KB5132061 and Windows judged it compatible. The automatic switch only happens on supported hardware, and not if you or your admin already turned it off.
My PC won't boot after Memory Integrity turned on. What now?
Windows can turn the feature back off automatically if the PC crashes during boot soon after it is enabled. If that does not happen, Microsoft documents a fix from the Windows Recovery Environment: set the registry value Enabled to 0 under HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity, then restart.
Is this related to the KB5132061 install errors?
Some reports link them, but Microsoft ties the install failures to PCs that had the October preview update. If your update keeps failing, see our guide on how to fix KB5132061.