NTLM Enhanced Blocking
Verified with Windows 11 25H2 — updated on September 15, 2026 Supported on: At least Windows 11 Version 24H2
Shipped in a Windows update: not in the official ADMX package (Administrative Templates (.admx) for Windows 11 Oct 2025 Update), present no later than KB5124008 (build 26200.9445).
Path in the GPO console
Computer Configuration\Administrative Templates\System\NTLM Registry
Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters - Value name:
-
EnhancedNtlmBlocksREG_DWORD - Enabled:
1- Disabled:
0
Description
This policy setting allows the NTLM security package to block NTLM authentication requests based on the new, enhanced blocking policies at the Machine level. These enhanced blocking policies allow you to block NTLM authentication based on new criteria, such as the type of the account, the role of the device, or the type of application. If the overall policy is set to "Disabled" or "Not Configured", the subsettings below will not take effect. If the overall policy is set to "Enabled", the subpolicies below will take effect based on their configuration. Unless configured, all policies are set to "Audit" mode. Policies that are set to "Audit" will log a warning about the NTLM request that could be blocked, but will not block it. Multiple policies that are marked as "Audit" can be enabled at the same time, and they will be logged in an unified event log. If any policy is marked as "Enabled", the NTLM authentication request will be blocked if it matches the criteria of the policy. If multiple policies are marked as "Enabled", the NTLM authentication request will be blocked if it matches the criteria of any of the policies. An event log will be generated for the first policy that blocks the NTLM authentication. In scenarios where there are both "Audit" and "Enabled" policies, the "Enabled" policy will take precedence. All of the enhanced blocking policies outlined here share the same allow list, which specifies the accounts, devices, and applications that are allowed to use NTLM authentication. The allow list can contain a series of target names or SPNs to allow the authentication. For more information, please visit aka.ms/ntlmlogandblock.
Export Builder
BETAConfigure 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: NTLM Enhanced Blocking
; State: Enabled
; Supported on: At least Windows 11 Version 24H2
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters]
"EnhancedNtlmBlocks"=dword:00000001
"BlockDomainAccountSSO"=dword:00000001
"BlockDomainControllerAuth"=dword:00000001
"EnforceMachineBinding"=dword:00000001
"BlockAll"=dword:00000001
"EnhancedMachineBlockingAllowList"=hex(7):00,00
; REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnhancedNtlmBlocks' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainAccountSSO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainControllerAuth' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnforceMachineBinding' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockAll' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnhancedMachineBlockingAllowList' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.Intune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnhancedNtlmBlocks' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockDomainAccountSSO' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockDomainControllerAuth' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnforceMachineBinding' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockAll' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnhancedMachineBlockingAllowList' -Expected @() -Kind MultiString)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnhancedNtlmBlocks' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainAccountSSO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainControllerAuth' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnforceMachineBinding' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockAll' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnhancedMachineBlockingAllowList' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.SCCM scripts
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnhancedNtlmBlocks' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockDomainAccountSSO' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockDomainControllerAuth' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnforceMachineBinding' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'BlockAll' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters' -Name 'EnhancedMachineBlockingAllowList' -Expected @() -Kind MultiString)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: NTLM Enhanced Blocking
# State: Enabled
# Supported on: At least Windows 11 Version 24H2
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\NTLM\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnhancedNtlmBlocks' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainAccountSSO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockDomainControllerAuth' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnforceMachineBinding' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'BlockAll' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'EnhancedMachineBlockingAllowList' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.Building a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.