Skip to main content

Disable Sync Host

Apply Now
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: Medium

    System Functionality / Data Loss Risk: Moderate

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

    This action improves privacy with some 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 turns off the Sync Host (OneSyncSvc) service.

This service syncs mail, contacts, calendars, and other user data across devices and apps 1.

Disabling this service stops the automatic sharing of personal information, enhancing privacy.

This script is recommended for individuals prioritizing the security of their personal data over the functionality of data synchronization.

Caution

Mail and other applications relying on synchronized data may not perform as intended without this service 1.

Use with Caution

This script is only recommended if you understand its implications.

Some non-critical or features may no longer function correctly after running this script.

This script can be fully reversed to restore changes if something goes wrong.

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 Sync Host" 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 Sync Host" 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 Sync Host
    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
:: Disable per-user "OneSyncSvc" service for all users
:: Disable the service `OneSyncSvc` 
PowerShell -ExecutionPolicy Unrestricted -Command "$serviceQuery = 'OneSyncSvc'; $stopWithDependencies= $false; <# -- 1. Skip if service does not exist #>; $service = Get-Service -Name $serviceQuery -ErrorAction SilentlyContinue; if(!$service) { Write-Host "^""Service query `"^""$serviceQuery`"^"" did not yield any results, no need to disable it."^""; Exit 0; }; $serviceName = $service.Name; Write-Host "^""Disabling service: `"^""$serviceName`"^""."^""; <# -- 2. Stop if running #>; if ($service.Status -eq [System.ServiceProcess.ServiceControllerStatus]::Running) { Write-Host "^""`"^""$serviceName`"^"" is running, attempting to stop it."^""; try { Write-Host "^""Stopping the service `"^""$serviceName`"^""."^""; $stopParams = @{ Name = $ServiceName; Force = $true; ErrorAction = 'Stop'; }; if (-not $stopWithDependencies) { $stopParams['NoWait'] = $true; }; Stop-Service @stopParams; Write-Host "^""Stopped `"^""$serviceName`"^"" successfully."^""; } catch { if ($_.FullyQualifiedErrorId -eq 'CouldNotStopService,Microsoft.PowerShell.Commands.StopServiceCommand') { Write-Warning "^""The service `"^""$serviceName`"^"" does not accept a stop command and may need to be stopped manually or on reboot."^""; } else { Write-Warning "^""Failed to stop service `"^""$ServiceName`"^"". It will be stopped after reboot. Error: $($_.Exception.Message)"^""; }; }; } else { Write-Host "^""`"^""$serviceName`"^"" is not running, no need to stop."^""; }; <# -- 3. Skip if service info is not found in registry #>; $registryKey = "^""HKLM:\SYSTEM\CurrentControlSet\Services\$serviceName"^""; if (-Not (Test-Path $registryKey)) { Write-Host "^""`"^""$registryKey`"^"" is not found in registry, cannot enable it."^""; Exit 0; }; <# -- 4. Skip if already disabled #>; if( $(Get-ItemProperty -Path "^""$registryKey"^"").Start -eq 4) { Write-Host "^""`"^""$serviceName`"^"" is already disabled from start, no further action is needed."^""; Exit 0; }; <# -- 5. Disable service #>; try { Set-ItemProperty -LiteralPath $registryKey -Name "^""Start"^"" -Value 4 -ErrorAction Stop; Write-Host 'Successfully disabled the service. It will not start automatically on next boot.'; } catch { Write-Error "^""Failed to disable the service. Error: $($_.Exception.Message)"^""; Exit 1; }"
:: Disable per-user "OneSyncSvc" service for individual user accounts
:: Disable the service `OneSyncSvc_*` 
PowerShell -ExecutionPolicy Unrestricted -Command "$serviceQuery = 'OneSyncSvc_*'; $stopWithDependencies= $false; <# -- 1. Skip if service does not exist #>; $service = Get-Service -Name $serviceQuery -ErrorAction SilentlyContinue; if(!$service) { Write-Host "^""Service query `"^""$serviceQuery`"^"" did not yield any results, no need to disable it."^""; Exit 0; }; $serviceName = $service.Name; Write-Host "^""Disabling service: `"^""$serviceName`"^""."^""; <# -- 2. Stop if running #>; if ($service.Status -eq [System.ServiceProcess.ServiceControllerStatus]::Running) { Write-Host "^""`"^""$serviceName`"^"" is running, attempting to stop it."^""; try { Write-Host "^""Stopping the service `"^""$serviceName`"^""."^""; $stopParams = @{ Name = $ServiceName; Force = $true; ErrorAction = 'Stop'; }; if (-not $stopWithDependencies) { $stopParams['NoWait'] = $true; }; Stop-Service @stopParams; Write-Host "^""Stopped `"^""$serviceName`"^"" successfully."^""; } catch { if ($_.FullyQualifiedErrorId -eq 'CouldNotStopService,Microsoft.PowerShell.Commands.StopServiceCommand') { Write-Warning "^""The service `"^""$serviceName`"^"" does not accept a stop command and may need to be stopped manually or on reboot."^""; } else { Write-Warning "^""Failed to stop service `"^""$ServiceName`"^"". It will be stopped after reboot. Error: $($_.Exception.Message)"^""; }; }; } else { Write-Host "^""`"^""$serviceName`"^"" is not running, no need to stop."^""; }; <# -- 3. Skip if service info is not found in registry #>; $registryKey = "^""HKLM:\SYSTEM\CurrentControlSet\Services\$serviceName"^""; if (-Not (Test-Path $registryKey)) { Write-Host "^""`"^""$registryKey`"^"" is not found in registry, cannot enable it."^""; Exit 0; }; <# -- 4. Skip if already disabled #>; if( $(Get-ItemProperty -Path "^""$registryKey"^"").Start -eq 4) { Write-Host "^""`"^""$serviceName`"^"" is already disabled from start, no further action is needed."^""; Exit 0; }; <# -- 5. Disable service #>; try { Set-ItemProperty -LiteralPath $registryKey -Name "^""Start"^"" -Value 4 -ErrorAction Stop; Write-Host 'Successfully disabled the service. It will not start automatically on next boot.'; } catch { Write-Error "^""Failed to disable the service. Error: $($_.Exception.Message)"^""; Exit 1; }"
Help

How to apply or restore "Disable Sync Host" 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

    Copy the code:
    Copy Apply Code Copy Revert 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

Similar Guides​

Wider Goal​

Guides below includes this guide to achieve a wider goal.

See other more general settings that includes this one as one of its actions.

These plans combine multiple privacy settings, including this one, for stronger protection.

This category contains scripts that improve privacy by turning off services that synchronize mail, contacts, calendars, and other user data. Turning off these serv...
Visit category page

Same Goal​

Another guide in Disable synchronization of mail, contacts, calendar, and user data 

See settings that are in the same category as this guide.

Using other actions in the same category may help you achieve your goal better.

Disable User Data Storage

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
About Us

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.

Review Change History Our Change Process