Smart App Control Grayed Out After KB5127648 Update Fix
You turned Smart App Control off once, and now the On option is grayed out so it cannot be switched back. This started with the October 2026 security update KB5127648, and Microsoft has officially confirmed it as a known issue.
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On 13 October 2026, Microsoft released KB5127648, the monthly security update for Windows 11 versions 24H2, 25H2 and 26H2. Soon after, Microsoft added a known issue to its own release notes: on some PCs, if Smart App Control was turned off before the update, the option to turn it on under Windows Security, App and browser control is now grayed out. PCs where Smart App Control was already on are not affected and stay protected. Microsoft has published an official workaround, and that is exactly what this guide applies — two commands, one restart.
Windows Security — App & browser control
Smart App ControlOff
OnGRAYED OUT
EvaluationSelectable
OffSelected
What the bug looks like: the On option cannot be selected, even though the page itself opens normally.
1
Confirm It Is Really This Bug
Not every grayed out setting is this issue. This bug has a very specific pattern, so check first.
Open Settings then Windows Update then Update history and confirm KB5127648 was installed in October 2026
You had turned Smart App Control off at some point before this update
Now the On option under Windows Security, App and browser control, Smart App Control is grayed out
If Smart App Control was already On before the update, you are not affected — your PC is protected as usual and you do not need this guide
2
Take a Backup Before Touching the Registry
Microsoft's workaround uses the registry, and Microsoft itself recommends a backup first. This takes one minute and removes all risk.
Create a restore point: search Create a restore point in Start, open it, and click Create
Or open Command Prompt as administrator and export the policy branch with reg export "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement" C:\FeatureManagement-backup.reg
If anything ever needs undoing, double-clicking that .reg file restores the old values
3
Run Microsoft's Two Workaround Commands ⭐
These are the exact commands from Microsoft's KB5127648 advisory. They add two feature override values and restore the ability to turn Smart App Control on.
Open Command Prompt as administrator (right-click Start, then Terminal (Admin) or Command Prompt (Admin))
Run the first command: reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2883193997 /t REG_DWORD /d 1 /f
Run the second command: reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2850574478 /t REG_DWORD /d 1 /f
Each command should answer The operation completed successfully
Restart the PC — the change does not apply without a restart
After restart, open Windows Security, App and browser control, and the On option for Smart App Control should be selectable again
Both commands should complete successfully before you restart.
4
For Office PCs — Or Simply Wait for the Real Fix
Honest options if the registry route is not for you.
For managed office PCs, Microsoft also published a Group Policy route for IT administrators using its KB5074105 Feature Preview policies — the admin enables them and restarts the devices
For a home PC, there is no shame in waiting: Microsoft says a permanent fix is coming in an upcoming release, and the grayed out switch does not break anything else
Do not uninstall KB5127648 for this issue — it is a security update, and removing it exposes the PC to the vulnerabilities it patched
⚠️ One honest warning: Smart App Control is an extra protection layer, not your only shield. While it is off, Microsoft Defender antivirus keeps working normally. Apply the workaround if you want the layer back, but do not panic — and never download "fix tools" from random websites for this; the two commands above are the complete official workaround.
🎥 See the Command-Based Fix Method in the Full Video
This fix is pure command work. The full video shows how IT admins fix Windows problems with the CMD Toolkit, command by command.
Is my PC unprotected while Smart App Control is off
No. Smart App Control is an additional layer that blocks untrusted apps before they run. Your real-time antivirus, Microsoft Defender, keeps working whether Smart App Control is on or off, so the PC is not left unguarded.
Will Microsoft release a permanent fix for the grayed out switch
Yes, according to Microsoft's own KB5127648 notes, the company is working on a resolution that will arrive in an upcoming release. No exact date has been announced, which is why the registry workaround above is the current official path.
I never turned Smart App Control off. Am I affected
No. Microsoft has limited this known issue to devices where Smart App Control had already been turned off. If yours is on, it stays on and keeps protecting the PC exactly as before the update.
This guide is based on Microsoft's KB5127648 advisory and the Technical Anshu video above • Stuck on a step? Ask in the video comments and the community will help 🙏