# FileCoAuth.exe

Application Process: Microsoft Corporation

Also called filecoauth, file co-authoring, onedrive file co-authoring

Windows, Application

Office file co-authoring and sync lock helper for OneDrive and SharePoint. It coordinates who holds the file. It is not WINWORD.EXE.

## What you need to know

FileCoAuth is co-authoring lock helper, not WINWORD itself.

FileCoAuth.exe manages co-authoring locks for Office files on OneDrive and SharePoint. WINWORD.EXE still edits the document. A burst of short FileCoAuth rows is often COM embedding, not a second Word.

- **Safe?**: Yes, with Office and OneDrive

  **Is it Word?**: No. This is the lock helper

  **Many short copies?**: COM launch, then it can exit

Feex says

If FileCoAuth flickers while I have a shared Word file open, I treat that as the lock helper. I do not end WINWORD to "stop co-authoring malware."

## What is FileCoAuth.exe?

FileCoAuth.exe is the co-authoring lock helper, not WINWORD.EXE. It lives next to the OneDrive client on many PCs, and Office can start it when a cloud document needs a lock.

## What does it do?

It coordinates sync locks so two people can edit one cloud file. It does not draw the Word ribbon. OneDrive.exe still owns the tray.

## Why is it running?

A Word, Excel, or PowerPoint file on OneDrive or SharePoint is open, or Office probed the lock. Short-lived copies with -Embedding are common.

## Why are there multiple copies?

Several short FileCoAuth.exe rows can be separate COM activations. None of those copies is a second WINWORD.EXE.

## Is it safe?

Usually safe

A Microsoft-signed FileCoAuth under the OneDrive version folder or Office16 is the helper. A FileCoAuth.exe in Temp is not. This is still not Word.

A legitimate copy normally runs from:

`C:\Users\<you>\AppData\Local\Microsoft\OneDrive\<version>\FileCoAuth.exe`

- Also seen under Microsoft Office\root\Office16
- Often started with -Embedding
- Not WINWORD.EXE

## Can I end it?

Cloud file locks can fail

Ending FileCoAuth.exe can drop a co-authoring session. The document window is still WINWORD.EXE. Save in Word if the UI still responds.

## Can I remove it?

Unlink OneDrive or uninstall Office

Do not delete FileCoAuth.exe. Stop using cloud co-authoring by working on a local copy, or unlink OneDrive. Deleting WINWORD does not remove this helper.

## Should it start with Windows?

Office or OneDrive starts it on demand. It is not a Startup Apps entry named FileCoAuth.

## Normal resource behavior

These are contextual labels, not universal averages.

- **CPU**: Usually a short burst when a cloud Office file opens

  **Memory**: Small

  **Disk**: Low

  **Network**: OneDrive or SharePoint lock traffic

## File information

| Executable name        | FileCoAuth.exe                                                               |
| ---------------------- | ---------------------------------------------------------------------------- |
| Common legitimate path | C:\Users\\\<you>\AppData\Local\Microsoft\OneDrive\\\<version>\FileCoAuth.exe |
| Publisher              | Microsoft Corporation                                                        |
| Signature expectation  | Signed by Microsoft Windows                                                  |

## Common problems

### Many processes scare people

COM can start a helper per document probe. That is not a Word clone farm. Check how long each row lives.

### File is locked after someone killed the helper

Close the Office app, then reopen the cloud file. Do not delete WINWORD to clear a SharePoint lock.

## Troubleshooting

Diagnose before you change anything destructive.

### Close the Office document, then reopen from OneDrive

That restarts the lock helper cleanly. Ending WINWORD mid-edit risks the buffer.

### Confirm the path is OneDrive or Office16

AppData\Local\Microsoft\OneDrive or Office16 is this article. A FileCoAuth.exe on the desktop is a different file.

## Technical details

Technical details

| Image name | FileCoAuth.exe                             |
| ---------- | ------------------------------------------ |
| Role       | Office / OneDrive co-authoring lock helper |

## Related

These entities connect to this article. Type is shown on every link.

[WINWORD.EXE: Application Process](https://feex.it/wiki/process/winword.exe)[OneDrive.exe: Application Process](https://feex.it/wiki/process/onedrive.exe)[OneDrive.Sync.Service.exe: Application Process](https://feex.it/wiki/process/onedrive.sync.service.exe)[EXCEL.EXE: Application Process](https://feex.it/wiki/process/excel.exe)

## Sources and verification

Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. [How we research](https://feex.it/wiki/research).

- [Microsoft Support: real-time co-authoring ](https://support.microsoft.com/office/collaborate-on-word-documents-with-real-time-co-authoring-7dd3040c-3f30-4fdd-bab0-8586492a1f1d)· Co-authoring is an Office plus OneDrive or SharePoint feature
- [Microsoft Support: OneDrive ](https://support.microsoft.com/onedrive)· Sync client hosts FileCoAuth on many PCs
- [Foxhole process map ](https://foxhole.feex.it/)· First-party samples on Windows PCs. Not a lab benchmark.

## Was this article useful?

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Quick facts

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- **Type**: Application Process

  **Publisher**: Microsoft Corporation

  **Executable**: FileCoAuth.exe

  **Typical path**: C:\Users\\\<you>\AppData\Local\Microsoft\OneDrive\\\<version>\FileCoAuth.exe

  **Mapped by Feex**: Seen on Windows PCs in Foxhole

  **Related process**: [WINWORD.EXE](https://feex.it/wiki/process/winword.exe)

Feex Reviewed: Last verified August 2026

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Source: [Canonical Feex Wiki page](https://feex.it/wiki/process/filecoauth.exe/)

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