msosync.exe

Microsoft Office Synchronization Service

System ProcessSafeOffice Sync

CPU Usage

2-12%

Memory

60-180 MB

Location

C:\Program Files\Microsoft Office\Office16\MSOSYNC.EXE

Publisher

Microsoft Corporation

Quick Answer

msosync.exe is safe. It's Microsoft's Office synchronization service that keeps Office apps and cloud storage in sync, ensuring documents, templates, and preferences stay up to date across devices.

Is it a Virus?

✔ NO - Safe

Must be in C:\Program Files\Microsoft Office\Office16\MSOSYNC.EXE

Can I Disable?

✔ YES - It will disable automatic sync and may affect cross-device data consistency

Disabling may stop background synchronization and Office sync features across devices

Verification

Ensure the file is signed by Microsoft Corporation and located in the official Office installation folder.

Verify digital signature via Properties > Digital Signatures to confirm Microsoft approval

What is msosync.exe?

msosync.exe is the Microsoft Office synchronization service responsible for coordinating file and settings sync between locally installed Office apps and cloud storage providers like OneDrive for Business and SharePoint. It runs in the background to ensure your documents, templates, and preferences stay current across devices and Office installations.

msosync.exe operates as a background service that communicates with your Office suite and cloud accounts. It uses a small, persistent process to batch and transfer changes, optimize network use, and handle conflict resolution when syncing files.

Quick Fact: Office synchronization started with modern Office suites to maintain consistency across devices and platforms, enabling seamless collaboration.

Types of msosync Processes

Sync Service Process: Core background service coordinating Office data sync
Background Tasks Processor: Handles scheduled sync jobs and queue management
Cloud Communication Module: Manages network transfers to OneDrive/SharePoint
Credential Cache: Maintains tokens for cloud services and re-authentication
Conflict Resolver: Resolves file conflicts during multi-device edits
UI Bridge (optional): Some Office components may initiate sync from the UI

Is msosync.exe Safe?

Yes, msosync.exe is safe when it's the legitimate Microsoft Office synchronization service installed by Microsoft and located in the Office installation directory.

Is msosync.exe a Virus or Malware?

The real msosync.exe is NOT a virus. However, malware can masquerade under similar names. Always verify location and signature.

How to Tell if msosync.exe is Legitimate or Malware

File Location:: Must be in C:\Program Files\Microsoft Office\Office16\MSOSYNC.EXE or C:\Program Files (x86)\Microsoft Office\Office16\MSOSYNC.EXE. Any other path is suspicious.
Digital Signature:: Right-click the file in Explorer -> Properties -> Digital Signatures. Should show "Microsoft Corporation".
Resource Usage:: Typical usage is 2-12% CPU, 60-180 MB memory during sync. Constant high usage when idle is suspicious.
Behavior:: Msosync.exe should run as part of Office startup or when Office activities require sync. It should not launch independently when Office is not installed.

Red Flags: If msosync.exe resides in unusual folders (like Temp, AppData\Local, or System32) or runs when Office isn't active, or lacks a digital signature, scan immediately. Beware of misleading names like "msosync32.exe".

Why Is msosync.exe Running on My PC?

msosync.exe runs to keep Office files and settings in sync across devices, cloud storage, and user profiles. It activates when Office apps require synchronization and when background sync is enabled.

Reasons it's running:

Active Office Sync: Office documents, templates, and settings are being synchronized with the cloud across devices.
Background Sync Tasks: As part of OneDrive/SharePoint integration, background jobs run to push changes.
Startup Launch: Office suite or OneDrive may start the sync client at Windows startup.
Token Refresh: OAuth tokens are refreshed to maintain access to cloud services.
Conflict Handling: The service resolves file version conflicts when edits occur on multiple devices.

Can I Disable or Remove msosync.exe?

Yes, you can disable msosync.exe. Disabling stops cloud-sync and offline sync features; however, Office data may not stay synchronized across devices.

How to Stop msosync.exe

Disable Startup: Task Manager > Startup tab > Disable Office Sync components or OneDrive integration (if present).
Pause Sync in Office/OneDrive: In Office settings or OneDrive settings, turn off background sync.
Close Office Apps: Close Word/Excel/PowerPoint to stop active syncing.
End Process (Temporary): Use Task Manager to End task for msosync.exe if needed (not recommended long-term).
Uninstall Office Features: Modify Office installation to remove specific sync components if desired.

How to Uninstall Office Sync Components

✔ Windows Settings → Apps → Apps & features → Microsoft Office → Change → Add or Remove Features → Turn off sync components
✔ Control Panel → Programs → Uninstall a program → Microsoft Office → Modify → Continue
✔ Consider alternative storage: use cloud services directly without Office-specific sync

Common Problems: High CPU or Memory Usage

If msosync.exe is consuming excessive resources, it may be performing active synchronization or facing conflicts with large files.

Common Causes & Solutions

Large files syncing: Pause sync on large files or exclude large folders.
Many active devices: Limit number of devices connected to the account.
Background apps: Disable nonessential background Office apps.
Outdated Office version: Update Office to latest version.
Conflicts during sync: Pause, resume, or re-sync to resolve conflicts.
Antivirus scanning Office files: Exclude Office synced folders from real-time scanning if safe.

Quick Fixes:
1. Quick Fixes:
2. 1. Open Task Manager (Shift+Esc in Windows) to identify syncing tasks consuming CPU.
3. 2. Pause or resume sync in OneDrive or Office settings.
4. 3. Clear local Office cache via Office options (settings).
5. 4. Update Office and Windows to the latest build.
6. 5. Reduce number of synchronized folders or large file transfers.

Frequently Asked Questions

What is msosync.exe and is it safe?

msosync.exe is the Microsoft Office synchronization service. If it is located in C:\Program Files\Microsoft Office\Office16\MSOSYNC.EXE and signed by Microsoft Corporation, it's legitimate.

What does msosync.exe do?

msosync.exe helps keep Office files and settings in sync across devices and cloud storage. It runs in the background as part of Office and OneDrive integration.

Why is msosync.exe using so much CPU?

If msosync.exe uses high CPU, check for large file sync operations, paused cloud services, or problematic Office add-ins. Pause sync to test.

Can I disable msosync.exe?

Yes, you can disable msosync.exe, but it will stop cross-device sync. It will not uninstall Office; you just won't sync through Office components.

Where is msosync.exe located?

To find the file, check C:\Program Files\Microsoft Office\Office16\MSOSYNC.EXE or C:\Program Files (x86)\Microsoft Office\Office16\MSOSYNC.EXE. It should be signed by Microsoft Corporation.

What should I do if I suspect msosync.exe is malware?

If you suspect malware, run a full antivirus scan and verify signatures. Do not delete files from system folders unless you are sure they belong to Office.

How do I stop msosync.exe from starting with Windows?

To stop it from starting at Windows startup, disable related startup items in Task Manager and adjust Office/OneDrive sync settings.