en-US windows computer

Convert warn verdict to block

Verified with Windows 11 25H2 — updated on July 10, 2026

Windows 11 25H2

Supported on: At least Windows Server 2016, Windows 10 Version 1709

Path in the GPO console

Computer Configuration\Administrative Templates\Windows Components\Microsoft Defender Antivirus\Network Inspection System

Description

Network protection inspects network traffic and determines whether it allows or blocks traffic or displays a warning. Disabled (Default): If Not Configured or Disabled, network protection will display a warning for warn verdicts. Enabled: If this setting is Enabled, network protection blocks network traffic instead of displaying a warning.

Registry

HKLM Software\Policies\Microsoft\Windows Defender\NIS

Value name: EnableConvertWarnToBlock

Enabled: EnableConvertWarnToBlock = 1

Disabled: EnableConvertWarnToBlock = 0

Export Builder

BETA

Configure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.

These exports write the registry — this is not a managed GPO.

.reg file

Windows Registry Editor Version 5.00

; Exported from gporais.com
; Policy: Convert warn verdict to block
; State: Enabled
; Supported on: At least Windows Server 2016, Windows 10 Version 1709

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\NIS]
"EnableConvertWarnToBlock"=dword:00000001
More formats (PowerShell, Intune, SCCM)

PowerShell

# Exported from gporais.com
# Policy: Convert warn verdict to block
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10 Version 1709

$path = 'HKLM:\Software\Policies\Microsoft\Windows Defender\NIS'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnableConvertWarnToBlock' -Value 1 -Type DWord

Building a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.

Open the Builder

Embed this policy on your site

What to embed
Theme

Adds one script line: the theme follows your site’s appearance and the height fits the content. If your site blocks scripts, the embed follows the visitor’s system theme.

Preview