How to Enable or Disable Microsoft Defender SmartScreen Check Apps and Files from Web in Windows 11

What Does SmartScreen Do?

Think of SmartScreen as a security guard for your downloads. It compares files and apps from the internet against Microsoft’s reputation data, which is a record of how widely a file is used and whether it has been reported as harmful. If a file is unknown or has a bad reputation, SmartScreen steps in. It works in the background, and you don’t need to start it.

On (default): SmartScreen warns you when a download might be dangerous. You can then choose to run it anyway or stop.

Off: SmartScreen stops checking and stops sending warnings. You get no alerts about potentially dangerous downloads, so your PC is more exposed. Turn it off only if you have a good reason, such as testing software you trust. Turn it back on when you’re done.

What You Need

You must be signed in as an administrator, or be able to enter an administrator’s credentials, to change these settings. ⚠️ Admin Required

If an option is greyed out, or you see the message “Some settings are managed by your organization”, a policy is controlling SmartScreen. This is common on work or school PCs. Settings made through Group Policy or the registry override the toggles in Windows Security.

The policy editor method (Option Three) needs Windows 11 Pro, Enterprise or Education. Home users should use Windows Security or the registry.

Option 1Using Windows Security (Easiest)

This method works on every edition of Windows 11, Home and Pro included. It is the best choice for most people.

These steps turn the smart screen defender check for apps and files on or off from Windows Security.

1. Open Windows Security. Search for it in the Start menu⊞, and the Windows Security window opens.
2. Click App & browser control in the left pane. The reputation and exploit protection options appear on the right.
3. Click Reputation-based protection settings. A list of SmartScreen toggles appears.
4. Set Check for apps and files to On or Off. If the toggle is greyed out, a policy is managing it, as described in the note above.
5. ⚠️ Admin Required: Click Yes when Windows asks for permission. The toggle now shows the new state.
6. Close Windows Security. No restart is needed for this method, and the change takes effect straight away.

That’s it. SmartScreen now checks downloads, or stops checking them, depending on the state you chose. To undo the change, repeat the steps and flip the toggle back.

Option 2Using Registry Editor

The Registry Editor is a tool for making low-level system changes. This method suits you if you are comfortable with advanced settings and want to turn SmartScreen on or off by editing a value. It works on Home and Pro.

Wrong registry changes can cause problems, so create a restore point or back up the registry before you start. The first list below sets SmartScreen to its default on state.

To Turn On SmartScreen (Default):

1. Press Win+R. The Run box opens.
2. Type regedit and press Enter. Select Yes if User Account Control asks, and Registry Editor opens.
3. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer. Paste the path into the address bar at the top of Registry Editor and press Enter.
4. Create the Explorer key if it is missing. Right-click CurrentVersion in the left pane, select New › Key, name it Explorer, and select it. Create any other missing key in the path the same way.
5. Create the SmartScreenEnabled value if it is missing. Right-click an empty area of the right pane, select New › String Value, and name it SmartScreenEnabled. If it is already there, skip this step.
6. Double-click SmartScreenEnabled. The Edit String window opens.
7. Type Warn in Value data and select OK. The value now shows in the right pane.

To Turn Off SmartScreen:

1. Press Win+R. The Run box opens.
2. Type regedit and press Enter. Select Yes if User Account Control asks, and Registry Editor opens.
3. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer. Paste the path into the address bar at the top of Registry Editor and press Enter.
4. Create the Explorer key if it is missing. Right-click CurrentVersion in the left pane, select New › Key, name it Explorer, and select it. Create any other missing key in the path the same way.
5. Create the SmartScreenEnabled value if it is missing. Right-click an empty area of the right pane, select New › String Value, and name it SmartScreenEnabled. If it is already there, skip this step.
6. Double-click SmartScreenEnabled. The Edit String window opens.
7. Type Off in Value data and select OK. The value now shows in the right pane.

That’s it. SmartScreen now uses the state you set in the registry. Follow only the list that matches what you want, and approve any administrator prompt.

Sign out and back in, or restart, if the change doesn’t show up in Windows Security. To undo it, follow the steps for the other option.

Option 3Using Local Group Policy Editor

Windows 11 Pro, Enterprise, and Education can manage SmartScreen with the Local Group Policy Editor, an administrative tool for system settings. Windows 11 Home doesn’t include it, so Home users should use Option One or one of the registry options. Group Policy lets you choose how SmartScreen behaves, not just whether it is on or off.

Warning: Choosing Off in this policy leaves downloads unchecked. Set the policy back to Not Configured or choose another option when you no longer need it off.

1. Press Win+R. The Run box opens.
2. Type gpedit.msc and press Enter. The Local Group Policy Editor opens.
3. Go to Computer Configuration › Administrative Templates › Windows Components › File Explorer📁 in the left pane. The policies appear in the right pane.
4. Double-click Configure Windows Defender SmartScreen. The policy window opens.
5. Select Enabled to see the choices. Selecting Disabled turns the policy off.
6. Choose one of these options:

   • WarnSmartScreen warns you about dangerous apps but lets you download them.
   • BlockSmartScreen stops you from downloading dangerous apps.
   • OffSmartScreen doesn’t check anything.
7. Click OK. The policy now shows its new state.
8. ⚠️ Admin Required: Close the Local Group Policy Editor. If the change doesn’t apply right away, sign out and back in or restart.

That’s it. SmartScreen now follows the mode you picked in the policy. To undo it, open the same policy and set it to Not Configured. Windows then goes back to using the setting in Windows Security.

Option 4Using Registry Editor (Advanced)

The Registry Editor also lets you set how SmartScreen handles risky downloads. It can show a warning, or it can block dangerous files outright. This gives you finer control than the on/off toggle, and it works on Home as well as Pro.

As before, back up the registry or create a restore point first, and sign in as an administrator.

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System" /v EnableSmartScreen /t REG_DWORD /d 1 /f

To Turn On SmartScreen and Warn About Dangerous Files:

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System" /v EnableSmartScreen /t REG_DWORD /d 1 /f

1. Press Win+R. The Run box opens.
2. Type regedit and press Enter. Select Yes if User Account Control asks, and Registry Editor opens.
3. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System. Paste the path into the address bar at the top of Registry Editor and press Enter.
4. Create the System key if it is missing. Right-click Windows in the left pane, select New › Key, name it System, and select it. Create any other missing key in the path the same way.
5. Create the ShellSmartScreenLevel value if it is missing. Right-click an empty area of the right pane, select New › String Value, and name it ShellSmartScreenLevel. If it is already there, skip this step.
6. Double-click ShellSmartScreenLevel. The Edit String window opens.
7. Type Warn in Value data and select OK. The value now shows in the right pane.

Warning: The next list turns SmartScreen off through a policy value, which leaves your downloads unchecked. Switch it back on afterwards.

To Turn Off SmartScreen:

1. Press Win+R. The Run box opens.
2. Type regedit and press Enter. Select Yes if User Account Control asks, and Registry Editor opens.
3. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System. Paste the path into the address bar at the top of Registry Editor and press Enter.
4. Create the System key if it is missing. Right-click Windows in the left pane, select New › Key, name it System, and select it. Create any other missing key in the path the same way.
5. Create the EnableSmartScreen value if it is missing. Right-click an empty area of the right pane, select New › DWORD (32-bit) Value, and name it EnableSmartScreen. If it is already there, skip this step.
6. Double-click EnableSmartScreen. The Edit DWORD (32-bit) Value window opens.
7. Set Base to Decimal, type 0 in Value data, and select OK. The value now shows in the right pane.

That’s it. SmartScreen now uses the mode you set in the registry. Follow only the steps for the result you want, then sign out and back in, or restart, so Windows picks up the change.

Follow the steps for a different option later to switch modes. If the Windows Security toggle is greyed out afterwards, that is expected, because a policy-based setting now controls SmartScreen.

Summary

If you turned SmartScreen off for testing, switch it back on in Windows Security as soon as you finish. If the toggle there stays greyed out, a policy or registry value from Option Three or Four is in control, so set the policy to Not Configured or follow the registry steps for the other option. On a work or school PC, your organization’s policy can also override your change.