Quick Answer
onenotem.exe is safe. It's part of Microsoft OneNote and uses multiple processes to handle UI, content rendering, and sync tasks for a responsive note-taking experience.
Is it a Virus?
✔ NO - Safe
Must be in C:\Program Files\Microsoft Office\root\Office16\ONENOTE.EXE or C:\Program Files (x86)\Microsoft Office\root\Office16\ONENOTE.EXE
Warning
Many processes normal
OneNote uses multiple processes for UI, rendering, and sync tasks; expect several onenotem-related processes when notebooks are open.
Can I Disable?
✔ YES
Close OneNote to reduce usage; disable startup and background sync if you don't need offline changes.
What is onenotem.exe?
onenotem.exe is the executable for Microsoft OneNote on Windows. OneNote employs a multi-process architecture to separate the user interface, content rendering, synchronization, and background tasks. This design improves responsiveness and stability when working with notebooks, pages, and ink input.
OneNote launches onenotem.exe to host the main UI and orchestrate sub-processes for rendering pages, syncing with OneDrive, and handling add-ins. This separation helps isolate crashes and keeps notebook data secure during operations.
Quick Fact: OneNote's multi-process approach helps keep notebooks responsive even with heavy attachments and ink input.
Types of OneNote Processes
- UI Process: Main OneNote window and user interface (1+ instances)
- Renderer Process: Page/content rendering and canvas drawing
- Sync Process: Background synchronization with OneDrive/SharePoint
- Ink/Recognition Process: Handwriting recognition and ink data handling
- Search/Indexing Process: Notebook search indexing and indexing tasks
- Background Task Process: Cache maintenance, autosave, and notifier tasks
Is onenotem.exe Safe?
Yes, onenotem.exe is safe when it's the legitimate Microsoft OneNote file downloaded from official sources.
Is onenotem.exe a Virus or Malware?
The real onenotem.exe is NOT a virus. Malware may imitate names to mislead you.
How to Tell if onenotem.exe is Legitimate or Malware
- File Location: Must be in
C:\Program Files\Microsoft Office\root\Office16\ONENOTE.EXE or C:\Program Files (x86)\Microsoft Office\root\Office16\ONENOTE.EXE.
- Digital Signature: Right-click on onenotem.exe in Task Manager → Open file location → Right-click on onenotem.exe → Properties → Digital Signatures. Should show "Microsoft Corporation".
- Resource Usage: Normal usage is 2-15% CPU per process and 100-500 MB total memory when actively used.
- Behavior: OneNote should run when you use the app. Persistent background activity when not opened is suspicious.
Red Flags: If onenotem.exe is located in unusual folders (like Temp or AppData), runs when OneNote isn't open, lacks a digital signature, or uses excessive resources constantly, scan with antivirus immediately. Be wary of similarly named files.
Why Is onenotem.exe Running on My PC?
onenotem.exe runs when you open Microsoft OneNote or when OneNote is configured to run in the background to keep notebooks synced and ready for quick access.
Reasons it's running:
- Active Note-Taking: You're editing or viewing a notebook; the UI and renderers are active.
- Background Synchronization: OneDrive/SharePoint sync tasks run to keep notebooks up to date.
- Startup Initialization: OneNote may start at Windows login or when Office starts.
- Notebook Indexing: Indexing and search indexing tasks run to support quick search.
- Ink/Handwriting Processing: If you use ink notes, handwriting recognition runs to convert ink.
Can I Disable or Remove onenotem.exe?
Yes, you can disable onenotem.exe. It's safe to close OneNote when not in use, and you can uninstall OneNote if you prefer a different productivity tool.
How to Stop onenotem.exe
- End OneNote Session: Close all OneNote notebooks or use File > Close All Notebooks
- End Process in Task Manager: Ctrl+Shift+Esc → Processes → select onenotem.exe → End Task
- Disable Startup: Task Manager → Startup tab → Disable Microsoft OneNote
- Disable Background Sync: OneNote Settings → Options → Save & Sync → Turn off background sync
- Uninstall If Desired: Windows Settings → Apps → OneNote → Uninstall
How to Uninstall OneNote
- ✔ Windows Settings → Apps → Apps & Features → Microsoft OneNote → Uninstall
- ✔ Control Panel → Programs → Programs and Features → Microsoft OneNote → Uninstall
- ✔ Consider using a different notes app if needed
Common Problems: High CPU or Memory Usage
If onenotem.exe is consuming excessive resources:
Common Causes & Solutions
- Many Notebooks Open: Close unused notebooks or switch to fewer open notebooks; reduce embedded content.
- Background Sync Frequent: Limit sync or adjust OneDrive/SharePoint settings to reduce hourly syncs.
- Heavy Ink Input: Disable handwriting features temporarily or reduce pen strokes during editing.
- Add-ins or Plugins: Disable or remove unnecessary add-ins in OneNote.
- Outdated App Version: Update OneNote from Microsoft 365 to latest version.
- Indexing & Cache: Clear cache or rebuild indexes via OneNote options, or run Disk Cleanup.
Quick Fixes:
1. Use Task Manager to identify heavy notebooks or sections.
2. Close unused notebooks, clear cache and data.
3. Disable unnecessary add-ins in OneNote.
4. Update OneNote to the latest version via Office apps.
5. Disable background sync in OneNote settings.
Frequently Asked Questions
Is onenotem.exe a virus?
No, the legitimate onenotem.exe from Microsoft is not a virus. Ensure the file is located in C:\Program Files\Microsoft Office\root\Office16\ONENOTE.EXE or similar Office paths and signed by Microsoft Corporation.
Why is onenotem.exe using so much CPU?
High CPU is usually caused by heavy notebooks, large attachments, or sync operations. Use OneNote Task Manager (Ctrl+Shift+Esc in OneNote) to identify the culprit and resolve.
Can I delete onenotem.exe?
You can uninstall OneNote or Office if you no longer need it. Your notebooks may sync or be saved locally depending on settings.
Can I disable onenotem.exe?
Yes, you can close OneNote or disable startup and background sync to reduce running processes.
Why does OneNote start at login?
OneNote can be configured to start with Windows or Office; disable in Task Manager Startup or in Office settings.
Why are there multiple onenotem.exe processes?
OneNote uses a multi-process architecture for UI, rendering, and sync; multiple processes may run to improve responsiveness and stability.