SmartScreen Registry Key for File Scanning

This article explains how to locate and configure the specific Windows Registry keys that manage the Windows Defender SmartScreen file scanning service. By modifying these keys in the Registry Editor (Regedit), administrators can enable, configure warning levels for, or disable SmartScreen file verification across the operating system.

Primary SmartScreen Registry Key

The primary registry key that controls the native Windows Explorer SmartScreen file scanning behavior is:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer

Inside this key, the behavior is determined by a string value named SmartScreenEnabled.

Configurable Values for SmartScreenEnabled

You can set the SmartScreenEnabled string (REG_SZ) to one of the following values:

• Warn: Displays a warning before running unrecognized or untrusted downloaded files, but allows the user to bypass the warning and proceed.
• RequireAdmin (or Block in older Windows builds): Displays a warning and requires administrator approval to run unrecognized files.
• Off: Completely disables the SmartScreen file scanning service in File Explorer.

Group Policy Managed Registry Key

If SmartScreen is being managed via centralized Group Policies, the configuration is stored in the system policies key instead:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System

Under this path, two values dictate the service’s functionality:

1. EnableSmartScreen (REG_DWORD):
   • 1 = SmartScreen is enabled.
   • 0 = SmartScreen is disabled.
2. ShellSmartScreenLevel (REG_SZ):
   • Warn = Prompts users with a bypassable warning.
   • Block = Blocks unrecognized applications entirely unless run by an administrator.

How to Modify the Setting

1. Press Win + R, type regedit, and press Enter.
2. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
3. Locate SmartScreenEnabled in the right-hand pane (or right-click the empty space, select New > String Value, and name it SmartScreenEnabled).
4. Double-click the value and enter Warn, RequireAdmin, or Off.
5. Click OK and restart your computer or restart the Windows Explorer process for changes to take effect.