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Disable Defender Antivirus service automatic launch

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Works with Windows 10 and 11Works with Windows Vista, XP, 7, 8, 10, 11, and Windows Server 2008 or newer.
  • Windows onlyThis script improves your privacy on Windows
  • Single actionThis page belongs to a script, containing basic changes to achieve a task.
  • Impact: High

    System Functionality / Data Loss Risk: High

    This action improves privacy with high impact when you run the recommended script.

  • Batch (batchfile)These changes use Windows system commands to update your settings.
  • Administrator rights requiredThis script requires privilege access to do the system changes
  • Fully reversible

    You can fully restore this action (revert back to the original behavior) using this website.

    The restore/revert methods provided here can help you fix issues.

Overview

This script prevents the Defender Antivirus service from starting automatically.

By default, Windows may automatically start the Defender Antivirus service (also called the Antimalware Service 1) under specific conditions 2 3. This script allows you to control when the service runs.

This script enhances privacy by preventing unexpected Defender Antivirus scans and data collection. It may improve system performance by stopping the service from using system resources without your permission.

However, it may reduce security by stopping Defender Antivirus from automatically activating against potential threats.

Caution

Disabling automatic launch may leave your system vulnerable if you forget to manually activate Defender Antivirus when needed.

Technical Details

This script sets the ServiceStartStates registry value to 0 in the Defender Antivirus registry key:

  • 0 indicates the service is turned off and won't start automatically; 1 means it will 4.
  • When a third-party antivirus is installed, Windows typically sets this value to 0 2.
  • Default values can vary; tests show that it is missing in fresh installations of both Windows 11 and Windows 10 5.
  • The MpSvc.dll 6 and MpClient.dll 7 files read this registry value to manage Defender Antivirus operations.
  1. Not Advised

    This script should only be used by advanced users.

    This script is not recommended for daily use as it breaks important functionality.

    Consider creating a system restore point before doing any changes.

  2. Security Trade-off

    This action prioritizes privacy over certain security features. It's not recommended and should only be used by advanced users after understanding its implications.

    Increased Privacy

    Enhanced privacy through reduced data collection and tracking

    Decreased Security

    Some security features will be disabled or limited

    This script can be reversed, this action allows you to can restore the system security.

Sources
PrivacyLearn.com maintains strict sourcing standards for accuracy, integrity and up-to-date content. Our content relies on authoritative sources including vendor documentation, industry standards, and verified research. Learn more about our verification process and quality standards in our editorial standards page.

Apply Now

Choose one of three ways to apply:

Download script

Download and run the script directly
  • No app needed
  • Offline usage
  • Easy-to-apply
  • Free
  • Open-source
Help

How to apply or restore "Disable Defender Antivirus service automatic launch" using script

  • ≈ 2 min to complete
  • Tools: Web Browser
  • Difficulty: Simple
  • ≈ 5 instructions
  1. 1

    Download

    Download the script file by clicking on the   Apply protection  button above.
    Use   Undo protection button above to restore changes.
  2. 2

    Keep the file

    If warned by your browser, keep the file.
  3. 3

    Open

    Open the downloaded file.
  4. 4

    Exit

    Once it's done, press any key to exit the window.
  5. 5

    Restart

    Restart your computer for all changes to take effect.

Apply with privacy.sexy

Guided, automated application with safety checks
  • Recommended for most users
  • Includes safety checks
  • Free
  • Open-source
  • Popular
  • Offline/Online usage
Open privacy.sexy
Help

How to apply or restore "Disable Defender Antivirus service automatic launch" using privacy.sexy

  • ≈ 3 min to complete
  • Tools: privacy.sexy
  • Difficulty: Simple
  • ≈ 4 instructions
privacy.sexy is free and open-source application that lets securely apply this action easily with more advanced options.
  1. 1

    Open or download

    Open or download the desktop application
  2. 2

    Choose script

    1. Search for the script name: Disable Defender Antivirus service automatic launch
    2. Check the script by clicking on the checkbox.
  3. 3

    Run

    Click on ▶️ Run button at the bottom of the page.

    This button only appears on desktop version (recommended). On browser, use 💾 Save button.

Run commands

Copy and run commands manually Requires technical knowledge
Apply changes
:: Set the registry value: "HKLM\SOFTWARE\Microsoft\Windows Defender!ServiceStartStates"
PowerShell -ExecutionPolicy Unrestricted -Command "function Invoke-AsTrustedInstaller($Script) { $principalSid = [System.Security.Principal.SecurityIdentifier]::new('S-1-5-80-956008885-3418522649-1831038044-1853292631-2271478464'); $principalName = $principalSid.Translate([System.Security.Principal.NTAccount]); $streamFile = New-TemporaryFile; $scriptFile = New-TemporaryFile; try { $scriptFile = Rename-Item -LiteralPath $scriptFile -NewName ($scriptFile.BaseName + '.ps1') -Force -PassThru; $Script | Out-File $scriptFile -Encoding UTF8; $taskName = "^""privacy$([char]0x002E)sexy invoke"^""; schtasks.exe /delete /tn $taskName /f 2>&1 | Out-Null; $executionCommand = "^""powershell.exe -ExecutionPolicy Bypass -File '$scriptFile' *>&1 | Out-File -FilePath '$streamFile' -Encoding UTF8"^""; $action = New-ScheduledTaskAction -Execute 'powershell.exe' -Argument "^""-ExecutionPolicy Bypass -Command `"^""$executionCommand`"^"""^""; $settings = New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries; Register-ScheduledTask -TaskName $taskName -Action $action -Settings $settings -Force -ErrorAction Stop | Out-Null; try { ($scheduleService = New-Object -ComObject Schedule.Service).Connect(); $scheduleService.GetFolder('\').GetTask($taskName).RunEx($null, 0, 0, $principalName) | Out-Null; $timeout = (Get-Date).AddMinutes(5); Write-Host "^""Running as $principalName"^""; while ((Get-ScheduledTaskInfo $taskName).LastTaskResult -eq 267009) { Start-Sleep -Milliseconds 200; if ((Get-Date) -gt $timeout) { Write-Warning 'Skipping: Timeout'; break; }; }; if (($result = (Get-ScheduledTaskInfo $taskName).LastTaskResult) -ne 0) { Write-Error "^""Failed, due to exit code: $result."^""; } } finally { schtasks.exe /delete /tn $taskName /f | Out-Null; }; Get-Content $streamFile } finally { Remove-Item $streamFile, $scriptFile; }; }; $cmd = '$registryPath = ''HKLM\SOFTWARE\Microsoft\Windows Defender'''+"^""`r`n"^""+'$data = ''0'''+"^""`r`n"^""+''+"^""`r`n"^""+'reg add ''HKLM\SOFTWARE\Microsoft\Windows Defender'' `'+"^""`r`n"^""+' /v ''ServiceStartStates'' `'+"^""`r`n"^""+' /t ''REG_DWORD'' `'+"^""`r`n"^""+' /d "^""$data"^"" `'+"^""`r`n"^""+' /f'; Invoke-AsTrustedInstaller $cmd"
Help

How to apply or restore "Disable Defender Antivirus service automatic launch" using commands

  • ≈ 2 min to complete
  • Tools: Command Prompt
  • Difficulty: Medium
  • ≈ 3 instructions
View step-by-step guide with screenshots
  1. 1

    Open Command Prompt

    Open Command Prompt as Administrator.
  2. 2

    Copy code

  3. 3

    Paste & run

    Paste the commands into Command Prompt and press Enter to run.

    Some changes require a system restart to take effect

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About the Creators

These people have authored this documentation and written its scripts:

  • Avatar of undergroundwires. The creator of PrivacyLearn and privacy.sexy. Black and white portrait showing a person wearing a polka dot tie and suit jacket, reflecting the professional expertise behind the privacy protection tools.
    • Certified security professional
    • 7+ years experience securing banks
    • Open-source developer since 2005
    • EU advisor, Public Speaker, Moderator
    • Hundreds across the globe
    • Testers, reviewers, developers
    • Companies, military agencies
    • Community since 2017

Reviewed By

This guide has undergone comprehensive auditing and peer review:
  • Expert review by undergroundwires

    • Verified technical accuracy and editorial standards
    • Assessed system impact and user privacy risks
  • Public review by large community

    • Privacy enthusiasts and professionals peer-reviewed
    • Millions of end-users tested across different environments

History

We continually monitor our guides, their impact and all other privacy options. We update our guides when new information becomes available. On every update, we publicly store who made the change, what has been changed, why the change was made and when the change was made.