Add-on List: registry value ListBox_Support_CLSID (Ext)UserHKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext

Policy ID: AddonManagement_AddOnList
Scope: Computer Configuration, User Configuration
Supported on: At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Windows Components › Internet Explorer › Security Features › Add-on Management

Registry

ListBox_Support_CLSID

REG_DWORDUserComputer

…\Software\Microsoft\Windows\CurrentVersion\Policies\ExtHKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext Current key
HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Ext

Enabled value: 1
Disabled value: 0

Apply with .reg · CMD · PowerShell

UserPer-account setting

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Ext]

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

CMD

:: Options (use only one)

:: Enabled
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext" /v "ListBox_Support_CLSID" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext" /v "ListBox_Support_CLSID" /t REG_DWORD /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext' -Name 'ListBox_Support_CLSID' -PropertyType DWord -Value 1 -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext' -Name 'ListBox_Support_CLSID' -PropertyType DWord -Value 0 -Force | Out-Null

ComputerMachine-wide setting

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Ext]

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

CMD

:: Options (use only one)

:: Enabled
reg add "HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Ext" /v "ListBox_Support_CLSID" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Ext" /v "ListBox_Support_CLSID" /t REG_DWORD /d 0 /f

PowerShell

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

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

(list values)

REG_SZComputerUser

…\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSIDHKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID

Enabled value: Depends on the option value
Element: Add-on List
Value type: REG_SZ
Add to existing value: true
Explicit value name: true

Apply with .reg · CMD · PowerShell

ComputerMachine-wide setting

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID]
"<enter name>"="<enter value>"

CMD

reg add "HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID" /v "<enter name>" /t REG_SZ /d "<enter value>" /f

PowerShell

New-Item -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID' -Name '<enter name>' -PropertyType String -Value '<enter value>' -Force | Out-Null

UserPer-account setting

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID]
"<enter name>"="<enter value>"

CMD

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID" /v "<enter name>" /t REG_SZ /d "<enter value>" /f

PowerShell

New-Item -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID' -Force | Out-Null
New-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID' -Name '<enter name>' -PropertyType String -Value '<enter value>' -Force | Out-Null