Enable headless UI mode: registry value UILockdownComputerHKLM\Software\Policies\Microsoft\Windows Defender\UX Configuration

Policy ID: UX_Configuration_UILockdown
Scope: Computer Configuration
Supported on: At least Windows Vista
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Windows Components › Microsoft Defender Antivirus › Client Interface

Registry

UILockdown

REG_DWORDComputer

HKLM\Software\Policies\Microsoft\Windows Defender\UX Configuration Current key

Enabled value: 1
Disabled value: 0

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\UX Configuration]

; Options (use only one)
; Enabled
"UILockdown"=dword:00000001
; Disabled
"UILockdown"=dword:00000000

CMD

:: Options (use only one)

:: Enabled
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\UX Configuration" /v "UILockdown" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\UX Configuration" /v "UILockdown" /t REG_DWORD /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKLM:\Software\Policies\Microsoft\Windows Defender\UX Configuration' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows Defender\UX Configuration' -Name 'UILockdown' -PropertyType DWord -Value 1 -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows Defender\UX Configuration' -Name 'UILockdown' -PropertyType DWord -Value 0 -Force | Out-Null