How To Turn On Smart App Control In Windows 11: A Complete Security Configuration Guide

Smart App Control is a robust cloud-backed security feature in Windows 11 designed to block untrusted, unsigned, and potentially malicious applications from executing on your system. To turn on this protection, your computer must run a clean installation of Windows 11 with diagnostic telemetry enabled. If the setting is greyed out, you must perform a system reset or complete reinstall to initialize its Code Integrity policies.

Windows 11 Security Requirements and Pre-Configuration Checklist

Before configuring Smart App Control (SAC), you must understand its rigid system dependencies. Unlike standard security features like Microsoft Defender SmartScreen, Smart App Control cannot simply be toggled on at any point in the lifecycle of an operating system. This is by design: Microsoft requires a clean baseline environment to guarantee that no pre-existing malware or untrusted binaries are running on your computer when the safety engine starts mapping your application landscape.

• OS Compatibility: Windows 11 Home, Pro, or Enterprise (Version 22H2 or later).
• Installation State: A fresh, clean installation of Windows 11, or a recently reset operating system image.
• Telemetry Status: Windows Optional Diagnostic Data must be fully active to allow cloud reputation checks.
• User Privilege level: Local Administrator access.
• Required Downtime: 10 to 30 minutes (up to 1 hour if a full operating system reset is required).
• Target Budget: Free (native OS utility).

Step-by-Step Configuration and Activation of Smart App Control

The steps below guide you through verifying your current state, activating the necessary diagnostic pathways, and turning on Smart App Control.

Step 1: Verify System Installation State and Telemetry Requirements

Smart App Control relies on continuous telemetry to verify unknown files against Microsoft’s security cloud. If you have disabled telemetry through privacy tools or local group policies, you must restore these settings.

1. Open your Windows Settings application by pressing the Windows Key + I.
2. Select Privacy and Security from the left sidebar navigation menu.
3. Click on Diagnostics and Feedback.
4. Locate the Send optional diagnostic data toggle and switch it to the On position. Without this enabled, the cloud reputation service cannot provide real-time classification for your local executables.

Warning: If you use third-party privacy software or custom debloating scripts that modify host files or block Microsoft telemetry servers, Smart App Control will fail to communicate with its cloud-based classification system and may automatically disable itself.

Step 2: Navigate to Windows Security Device Protection

Once telemetry is active, you must open the centralized security control suite to manage the app control parameters.

1. Click on the Start Menu, type Windows Security, and press Enter.
2. Inside the Windows Security interface, select App and browser control from the main dashboard or the left-hand navigation pane.
3. Locate the Smart App Control section at the top of the pane and click on the Smart App Control settings link.

Step 3: Configure the Operational State of Smart App Control

When you enter the Smart App Control configuration window, you will be presented with three distinct radio buttons: On, Evaluation, and Off.

1. Evaluation Mode: If your system was recently clean-installed, it will likely default to Evaluation mode. In this state, Windows quietly monitors your application usage pattern. It flags potential blocks without actually interrupting your workflow, determining if Smart App Control will cause excessive disruption based on your daily app choices.
2. On: Select this option to actively block unsigned apps, script files, and macros that do not meet Microsoft’s reputation criteria.
3. Off: Select this if you run developers' tools, unsigned homebrew software, or custom scripts.

Warning: Selecting Off is a permanent state change for that specific Windows installation. Once you toggle Smart App Control to Off, you cannot turn it back on without resetting or reinstalling Windows 11.

Step 4: Perform a System Reset to Force Enablement (If Greyed Out)

If the On and Evaluation choices are greyed out, your current Windows installation was upgraded from Windows 10, or it has been operational long enough without SAC initialized to disqualify it. To enable it, you must perform a clean reset.

1. Back up all vital personal data, application licenses, and configurations to an external drive or cloud storage.
2. Open Windows Settings (Windows Key + I) and select System.
3. Click on Recovery, then select the Reset PC button next to the Reset this PC menu.
4. Choose Keep my files to preserve personal data, or select Remove everything for a completely pristine OS image. Removing everything is the most reliable way to guarantee Smart App Control initializes correctly.
5. Choose Cloud download to get the latest secure system files, or Local reinstall to use your local storage drive.
6. Once the installation process completes and you finish the initial Windows out-of-box setup, immediately follow Step 1 and Step 2 to turn on Smart App Control before installing any third-party tools.

Pro-Tip: Developers or administrators who regularly work with command-line compilers, custom batch files, or unsigned PowerShell scripts should keep Smart App Control disabled or in Evaluation mode. Forcing it to On on a developer machine will cause recurrent, frustrating execution blocks during local build cycles.

Smart App Control Operational Modes and Technical Specifications

The table below outlines the precise behavioral differences, requirements, and policy parameters of the three operational modes within Smart App Control.

Resolving Smart App Control Blocks and Activation Failures

Scenario 1: The "On" and "Evaluation" options are greyed out in Windows Security

• Root Cause: The Windows installation is an upgrade from a previous version (such as Windows 10), or the OS baseline has been flagged as "dirty" because it ran for an extended period without active code integrity validation.
• Actionable Fix: Open Settings, navigate to System, click Recovery, and select Reset PC. Choose to perform a clean reinstall. Alternatively, you can download the Windows 11 Media Creation Tool, burn a bootable USB drive, format your primary partition, and execute a completely fresh installation of Windows 11.

Scenario 2: Smart App Control blocks a safe, custom-built corporate tool

• Root Cause: The software lacks a valid, trusted digital signature (such as a Sectigo or DigiCert Authenticode certificate), or the application has not built up sufficient reputation metrics within Microsoft’s global cloud intelligence graph.
• Actionable Fix: To run the application without turning off Smart App Control globally, the developer must digitally sign the application using a trusted code-signing certificate. If you are an end-user, you can attempt to unblock the file by right-clicking the executable, selecting Properties, ticking the Unblock checkbox at the bottom of the General tab, and clicking Apply.

Scenario 3: The settings revert to "Off" automatically after configuration

• Root Cause: Windows Optional Diagnostic Data has been disabled by Group Policy, local registry changes, or a third-party telemetry blocking tool.
• Actionable Fix: Open the Local Group Policy Editor by typing gpedit.msc in the Run dialog. Navigate to Computer Configuration, select Administrative Templates, click Windows Components, and select Data Collection and Preview Builds. Ensure that Allow Diagnostic Data is set to Enabled and configured to send Optional diagnostic data. Restart your computer and recheck the Smart App Control dashboard.

Frequently Asked Questions

Can I turn on Smart App Control without reinstalling Windows 11?

No. Under standard security protocols, Smart App Control requires a clean installation of Windows 11. This prevents pre-existing, dormant malware on your drive from being grandfathered in as safe during initialization. If your system is currently running an upgraded OS image, you must perform a system reset to toggle this security feature on.

What is the difference between Smart App Control and SmartScreen?

Microsoft Defender SmartScreen is a basic layer of protection that checks downloaded files against a list of known malicious sites and files. Smart App Control is a much deeper, kernel-level application control mechanism that uses artificial intelligence to actively block any unsigned or low-reputation execution attempt, even if the file was transferred via a local network drive or USB stick.

Does Smart App Control impact gaming or system performance?

Under normal conditions, Smart App Control has a negligible impact on system performance. The security validation occurs during the initial execution phase of an application. Once the binary signature and cloud reputation are verified, the operating system caches this trust status, allowing subsequent launches of the application to load at native hardware speeds.

How do I know if an app was blocked by Smart App Control?

When a binary execution is blocked, Windows 11 displays a native notification box labeled "Smart App Control blocked this app". This pop-up explicitly states that the app was blocked because it is unsigned or lacks a trusted reputation. You can also audit these events by opening the Windows Event Viewer and navigating to the AppLocker pack-packaging logs.

Secure Your Enterprise Infrastructure and PC Deployments

If you are managing deployment groups across an entire enterprise network, manual configuration is highly inefficient. Integrate automated provisioning scripts and centralize your endpoints by deploying Microsoft Intune policies or group policies to enforce Smart App Control at scale during initial imaging.