Turn on SmartScreen Filter scan
This policy controls whether SmartScreen Filter scans webpages in the Locked-Down Restricted Sites Zone for malicious content.
since 0.9.8.11
Purpose
Show registry keys (2)
HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Lockdown_Zones\4\2301HKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Lockdown_Zones\4\2301
This policy controls whether SmartScreen Filter scans webpages in the Locked-Down Restricted Sites Zone for malicious content. Registry value 2301 represents the Internet Explorer URL action URLACTION_ALLOW_APEVALUATION.
A REG_DWORD value of 0 (URLPOLICY_ALLOW) enables evaluation. A value of 3 (URLPOLICY_DISALLOW) disables it. When the policy is not defined, the user can choose whether SmartScreen Filter scans pages in this zone.
The HKLM entry represents the device-scoped policy, while the HKCU entry represents its user-scoped counterpart.
Notes
Security
When scanning is enabled, SmartScreen can compare visited pages with intelligence about reported phishing and malware sites and display a warning when it identifies a threat. This reduces the likelihood that users will unknowingly interact with known malicious content.
Disabling the scan removes this protection layer from pages processed under the affected locked-down security zone. It does not disable other protections such as Microsoft Defender Antivirus or SmartScreen in Microsoft Edge and the Windows shell.
SmartScreen can detect only threats for which sufficient characteristics or reputation data are available. Enabling the scan therefore does not guarantee that every malicious page will be identified.
Possible side effects
A page classified as suspicious or malicious can trigger a warning page and interrupt navigation. In rare cases, SmartScreen can also warn about a legitimate site incorrectly.
Notes
This policy applies only to the locked-down form of the Restricted Sites Zone under Lockdown_Zones\4. It does not configure the ordinary Restricted Sites Zone under Zones\4, nor does it configure SmartScreen globally for Microsoft Edge or Windows.
Settings under Lockdown_Zones are consulted only when the Internet security manager selects locked-down zone policies for the operation, such as during restricted-protocol processing.
In Internet Explorer 7, the same policy controls page evaluation by the earlier Phishing Filter.
Microsoft has deprecated SmartScreen in Internet Explorer and IE mode on updated systems running Windows 11 version 24H2 or 25H2 and Windows Server 2025. On those systems, this policy no longer causes SmartScreen to scan pages. SmartScreen in Microsoft Edge, the Windows shell, and other supported environments remains separate.
Microsoft documentation
Microsoft Learn: InternetExplorer Policy CSP – LockedDownRestrictedSitesZoneAllowSmartScreenIE
Microsoft Support: SmartScreen deprecation in Internet Explorer and IE Mode in Windows 11
Microsoft Learn: URL Action Flags
Microsoft Learn: URL Policy Flags