How to Harden a Windows 11 Endpoint

A practical hardening checklist for Windows 11 PCs in business environments. Covers BitLocker, Defender, attack surface reduction, application control, and more.

7 min readUpdated March 29, 2026

Overview section

A default Windows 11 installation is not secure enough for business use. While Microsoft has improved security defaults significantly (TPM 2.0 requirement, Secure Boot, VBS), many features are off by default and need to be explicitly configured.

This guide provides a practical hardening checklist organised by priority. It aligns with the CIS Benchmark for Windows 11 (v5.0.0) and Microsoft's security baselines. The guidance targets Windows 11 24H2 (the current release as of March 2026).

Priority 1: Essential (Do These First)section

Enable BitLocker full-disk encryption section

Protects data if a device is lost or stolen.

powershell

Enable-BitLocker -MountPoint "C:" -EncryptionMethod XtsAes256 -TpmProtector
Add-BitLockerKeyProtector -MountPoint "C:" -RecoveryPasswordProtector

See our full guide: Deploy BitLocker Across an Organisation

Enable Microsoft Defender Antivirus real-time protection section

Should be on by default, but verify:

powershell

Get-MpPreference | Select-Object DisableRealtimeMonitoring, DisableBehaviorMonitoring
# Both should be False

Enable tamper protection section

Prevents malware from disabling Defender:

Open Windows Security > Virus & threat protection > Manage settings
Toggle Tamper protection to On

Enable automatic Windows updates section

powershell

# Verify update service is running
Get-Service -Name wuauserv | Select-Object Status, StartType

Require strong passwords or Windows Hello section

Configure via Intune or local policy:

Minimum 12 characters
Complexity requirements enabled
Account lockout after 5 failed attempts

Priority 2: High (Do This Week)section

Enable Attack Surface Reduction (ASR) rules section

ASR rules block common attack techniques. Deploy via Intune or Group Policy.

The most impactful ASR rules:

powershell

# Block Office apps from creating child processes
Add-MpPreference -AttackSurfaceReductionRules_Ids D4F940AB-401B-4EFC-AADC-AD5F3C50688A -AttackSurfaceReductionRules_Actions Enabled

# Block Office apps from injecting code into other processes
Add-MpPreference -AttackSurfaceReductionRules_Ids 75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84 -AttackSurfaceReductionRules_Actions Enabled

# Block executable content from email client and webmail
Add-MpPreference -AttackSurfaceReductionRules_Ids BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550 -AttackSurfaceReductionRules_Actions Enabled

# Block credential stealing from LSASS
Add-MpPreference -AttackSurfaceReductionRules_Ids 9E6C4E1F-7D60-472F-BA1A-A39EF669E4B2 -AttackSurfaceReductionRules_Actions Enabled

# Block untrusted/unsigned processes from USB
Add-MpPreference -AttackSurfaceReductionRules_Ids B2B3F03D-6A65-4F7B-A9C7-1C7EF74A9BA4 -AttackSurfaceReductionRules_Actions Enabled

Warning

Run ASR rules in Audit mode first (AuditMode instead of Enabled) for 1-2 weeks to identify false positives before enforcement.

Disable unnecessary services section

powershell

# Disable Remote Desktop if not needed
Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Terminal Server" -Name "fDenyTSConnections" -Value 1

# Disable Remote Registry
Set-Service -Name RemoteRegistry -StartupType Disabled -ErrorAction SilentlyContinue

# Disable NetBIOS over TCP/IP (reduces lateral movement attack surface)
$adapters = Get-CimInstance Win32_NetworkAdapterConfiguration -Filter "IPEnabled=True"
$adapters | ForEach-Object { Invoke-CimMethod -InputObject $_ -MethodName SetTcpipNetbios -Arguments @{TcpipNetbiosOptions=2} } # 2 = Disable

Configure Windows Firewall section

Ensure the firewall is on for all profiles:

powershell

Set-NetFirewallProfile -Profile Domain,Public,Private -Enabled True

# Block all inbound by default, allow outbound
Set-NetFirewallProfile -Profile Domain,Public,Private -DefaultInboundAction Block -DefaultOutboundAction Allow

Enable Controlled Folder Access section

Protects against ransomware by blocking unauthorised apps from modifying files in protected folders:

powershell

Set-MpPreference -EnableControlledFolderAccess Enabled

Consider Smart App Control section

Smart App Control (available since Windows 11 22H2) uses AI-backed code signing verification and reputation analysis to block untrusted and potentially dangerous applications. It is a good option for endpoints that do not need to run niche or unsigned software.

Smart App Control can only be enabled on a fresh Windows installation or a reset PC. It cannot be enabled on an existing device that has been running without it
It starts in Evaluation mode and automatically turns on if it determines the device is a good fit
Once turned off, it cannot be re-enabled without resetting Windows

Smart App Control is best suited for standard user workstations (not developer machines or servers).

Priority 3: Medium (Do This Month)section

Enable Credential Guard section

Protects against credential theft by isolating LSASS in a virtualised container. On Windows 11 24H2 Enterprise, Credential Guard is enabled by default on capable hardware. For other editions, enable it manually:

powershell

# Enable via registry (requires VBS capable hardware)
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\LSA" -Name "LsaCfgFlags" -Value 1

Or deploy via Intune: Endpoint security > Account protection > Credential Guard.

Configure local admin account section

Rename the built-in Administrator account
Disable the built-in Administrator account if not needed
Use Windows LAPS (built into Windows 11 23H2 and later) for unique local admin passwords per device. A separate download is no longer required. Configure via Intune or Group Policy

powershell

# Disable built-in admin
Disable-LocalUser -Name "Administrator"

# Rename it (if leaving enabled for emergency)
Rename-LocalUser -Name "Administrator" -NewName "LocRecovery"

Restrict PowerShell section

powershell

# Enable PowerShell script block logging
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" -Name "EnableScriptBlockLogging" -Value 1

# Enable PowerShell transcription (logs all PS activity)
New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" -Force
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" -Name "EnableTranscripting" -Value 1
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" -Name "OutputDirectory" -Value "C:\PSTranscripts"

Disable SMBv1 section

SMBv1 is used by WannaCry and other worms:

powershell

# Disable SMBv1 client and server
Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol -NoRestart
Set-SmbServerConfiguration -EnableSMB1Protocol $false -Force

Enable audit logging section

Configure these audit policies for security monitoring:

powershell

# Enable logon event auditing
auditpol /set /subcategory:"Logon" /success:enable /failure:enable
auditpol /set /subcategory:"Account Lockout" /success:enable /failure:enable
auditpol /set /subcategory:"Logoff" /success:enable
auditpol /set /subcategory:"Special Logon" /success:enable

# Enable process creation auditing (critical for threat detection)
auditpol /set /subcategory:"Process Creation" /success:enable

# Enable command-line logging in process creation events
Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\Audit" -Name "ProcessCreationIncludeCmdLine_Enabled" -Value 1

Hardening Checklist Summary section

Control	Priority	Method
BitLocker encryption	Essential	Intune / GPO / Script
Defender real-time protection	Essential	Default (verify on)
Tamper protection	Essential	Windows Security
Automatic updates	Essential	Intune / GPO
Strong password policy	Essential	Intune / GPO
ASR rules	High	Intune / GPO / Script
Windows Firewall (all profiles)	High	GPO / Script
Controlled Folder Access	High	Intune / Script
Disable unnecessary services	High	GPO / Script
Credential Guard	Medium	Intune / Registry
Windows LAPS for local admin	Medium	Intune / GPO (built-in)
PowerShell logging	Medium	GPO / Registry
Disable SMBv1	Medium	PowerShell
Audit logging	Medium	auditpol / GPO

Verification Script section

Run this script to check the current hardening status of a device:

powershell

Write-Host "=== Windows 11 Hardening Status ===" -ForegroundColor Cyan

# BitLocker
$bl = Get-BitLockerVolume -MountPoint "C:" -ErrorAction SilentlyContinue
Write-Host "BitLocker:          $(if ($bl.VolumeStatus -eq 'FullyEncrypted') {'PASS'} else {'FAIL'})"

# Defender
$mp = Get-MpPreference
Write-Host "Real-time protect:  $(if (-not $mp.DisableRealtimeMonitoring) {'PASS'} else {'FAIL'})"
Write-Host "Tamper protection:  $(if ((Get-MpComputerStatus).IsTamperProtected) {'PASS'} else {'FAIL'})"

# Firewall
$fw = Get-NetFirewallProfile | Where-Object { -not $_.Enabled }
Write-Host "Firewall (all):     $(if ($fw.Count -eq 0) {'PASS'} else {'FAIL'})"

# SMBv1
$smb1 = Get-SmbServerConfiguration | Select-Object -ExpandProperty EnableSMB1Protocol
Write-Host "SMBv1 disabled:     $(if (-not $smb1) {'PASS'} else {'FAIL'})"

# Controlled Folder
Write-Host "Controlled Folder:  $(if ($mp.EnableControlledFolderAccess -eq 1) {'PASS'} else {'FAIL'})"

Tip

For full CIS Benchmark compliance, download the CIS Benchmark for Windows 11 v5.0.0 (or the latest available version) and compare your configuration against all 300+ controls. The items in this guide cover the highest-impact controls that protect against the most common attack vectors.

Need help maintaining secure devices?section

Explore managed IT support for ongoing administration and security management. For a one-off configuration issue, see on-demand remote IT support.

Windows 11Endpoint SecurityHardeningCIS BenchmarksDefender

GuidesHow to Deploy BitLocker Encryption Across an OrganisationA complete guide to deploying BitLocker drive encryption across your business using Intune, Group Policy, or PowerShell — including Microsoft Entra ID key backup.Read GuidesConditional Access Policies in Entra IDA practical guide to creating Conditional Access policies in Microsoft Entra ID to enforce MFA, block risky sign-ins, and require compliant devices for Microsoft 365 access.Read SecurityCompromised M365 Account Response PlanA step-by-step incident response checklist for when a Microsoft 365 account is compromised. Covers containment, investigation, remediation, and prevention.Read

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