Block NTLM (LM, NTLM, NTLMv2)
Verified with Windows 11 25H2 — updated on July 10, 2026
Supported on: At least Windows Server 2025, Windows 11
Path in the GPO console
Computer Configuration\Administrative Templates\Network\Lanman Workstation Description
This policy controls if the SMB client will block NTLM for remote connection authentication. If you enable this policy setting, the SMB client won't use NTLM for remote connection authentication. If you disable or do not configure this policy setting, the SMB client can still use NTLM.
Registry
HKLM
Software\Policies\Microsoft\Windows\LanmanWorkstation Value name: BlockNTLM
Enabled: BlockNTLM = 1
Disabled: BlockNTLM = 0
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: Block NTLM (LM, NTLM, NTLMv2)
; State: Enabled
; Supported on: At least Windows Server 2025, Windows 11
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\LanmanWorkstation]
"BlockNTLM"=dword:00000001More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BlockNTLM' -Value 1 -Type DWordIntune 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: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation' -Name 'BlockNTLM' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BlockNTLM' -Value 1 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
# 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: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation' -Name 'BlockNTLM' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Block NTLM (LM, NTLM, NTLMv2)
# State: Enabled
# Supported on: At least Windows Server 2025, Windows 11
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BlockNTLM' -Value 1 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.