Allow delegating default credentials with NTLM-only server authentication: registry value AllowDefCredentialsWhenNTLMOnly and 1 more (CredentialsDelegation)ComputerHKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation

Policy ID: AllowDefCredentialsWhenNTLMOnly
Scope: Computer Configuration
Supported on: At least Windows Vista
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: System › Credentials Delegation

Registry

AllowDefCredentialsWhenNTLMOnly

REG_DWORDComputer

HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation 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\CredentialsDelegation]

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

CMD

:: Options (use only one)

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

PowerShell

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

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

(list values)

REG_SZComputer

HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly

Enabled value: Depends on the option value
Element: Add servers to the list:
Value type: REG_SZ
Value name prefix: -
Add to existing value: true

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly]

; Add one value per list entry, increasing the number
"1"="<enter value>"
"2"="<enter value>"

CMD

:: Add one value per list entry, increasing the number

reg add "HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly" /v "1" /t REG_SZ /d "<enter value>" /f
reg add "HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly" /v "2" /t REG_SZ /d "<enter value>" /f

PowerShell

# Add one value per list entry, increasing the number

New-Item -Path 'HKLM:\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly' -Name '1' -PropertyType String -Value '<enter value>' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\CredentialsDelegation\AllowDefCredentialsWhenNTLMOnly' -Name '2' -PropertyType String -Value '<enter value>' -Force | Out-Null

ConcatenateDefaults_AllowDefNTLMOnly

REG_DWORDComputer

HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation Current key

Checked: 1
Unchecked: 0
Element: Concatenate OS defaults with input above
Value type: REG_DWORD

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CredentialsDelegation]

; Options (use only one)
; Checked
"ConcatenateDefaults_AllowDefNTLMOnly"=dword:00000001
; Unchecked
"ConcatenateDefaults_AllowDefNTLMOnly"=dword:00000000

CMD

:: Options (use only one)

:: Checked
reg add "HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation" /v "ConcatenateDefaults_AllowDefNTLMOnly" /t REG_DWORD /d 1 /f
:: Unchecked
reg add "HKLM\Software\Policies\Microsoft\Windows\CredentialsDelegation" /v "ConcatenateDefaults_AllowDefNTLMOnly" /t REG_DWORD /d 0 /f

PowerShell

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

# Options (use only one)
# Checked
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\CredentialsDelegation' -Name 'ConcatenateDefaults_AllowDefNTLMOnly' -PropertyType DWord -Value 1 -Force | Out-Null
# Unchecked
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\CredentialsDelegation' -Name 'ConcatenateDefaults_AllowDefNTLMOnly' -PropertyType DWord -Value 0 -Force | Out-Null