Mandate the minimum version of SMB: registry value MinSmb2Dialect (LanmanServer)ComputerHKLM\Software\Policies\Microsoft\Windows\LanmanServer

Policy ID: Pol_MinSmb2Dialect
Scope: Computer Configuration
Supported on: At least Windows Server 2022, Windows 11
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Network › Lanman Server

Registry

MinSmb2Dialect

REG_DWORDComputer

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

Enabled value: Depends on the option value
Element: Version:

Options
Item	Stored value
SMB 2.0.2	514
SMB 2.1.0	528
SMB 3.0.0	768
SMB 3.0.2	770
SMB 3.1.1	785

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

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

; Options (use only one)
; SMB 2.0.2
"MinSmb2Dialect"=dword:00000202
; SMB 2.1.0
"MinSmb2Dialect"=dword:00000210
; SMB 3.0.0
"MinSmb2Dialect"=dword:00000300
; SMB 3.0.2
"MinSmb2Dialect"=dword:00000302
; SMB 3.1.1
"MinSmb2Dialect"=dword:00000311

CMD

:: Options (use only one)

:: SMB 2.0.2
reg add "HKLM\Software\Policies\Microsoft\Windows\LanmanServer" /v "MinSmb2Dialect" /t REG_DWORD /d 514 /f
:: SMB 2.1.0
reg add "HKLM\Software\Policies\Microsoft\Windows\LanmanServer" /v "MinSmb2Dialect" /t REG_DWORD /d 528 /f
:: SMB 3.0.0
reg add "HKLM\Software\Policies\Microsoft\Windows\LanmanServer" /v "MinSmb2Dialect" /t REG_DWORD /d 768 /f
:: SMB 3.0.2
reg add "HKLM\Software\Policies\Microsoft\Windows\LanmanServer" /v "MinSmb2Dialect" /t REG_DWORD /d 770 /f
:: SMB 3.1.1
reg add "HKLM\Software\Policies\Microsoft\Windows\LanmanServer" /v "MinSmb2Dialect" /t REG_DWORD /d 785 /f

PowerShell

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

# Options (use only one)
# SMB 2.0.2
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanServer' -Name 'MinSmb2Dialect' -PropertyType DWord -Value 514 -Force | Out-Null
# SMB 2.1.0
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanServer' -Name 'MinSmb2Dialect' -PropertyType DWord -Value 528 -Force | Out-Null
# SMB 3.0.0
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanServer' -Name 'MinSmb2Dialect' -PropertyType DWord -Value 768 -Force | Out-Null
# SMB 3.0.2
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanServer' -Name 'MinSmb2Dialect' -PropertyType DWord -Value 770 -Force | Out-Null
# SMB 3.1.1
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanServer' -Name 'MinSmb2Dialect' -PropertyType DWord -Value 785 -Force | Out-Null