Quick Answer
lync.exe is safe. It's Microsoft's official Lync/Skype for Business client, running in multiple processes to separate UI, messaging, and media components for reliability.
Is it a Virus?
✔ NO - Safe
Must be in C:\Program Files\Microsoft Office\root\Office16 or C:\Program Files (x86)\Microsoft Office\root\Office16
Warning
Multiple processes normal
Lync can spawn several processes for chat, presence, and media during active use
Can I Disable?
✔ YES
Sign out from Lync and prevent startup; you can remove the Skype for Business/Lync component if not required
What is lync.exe?
lync.exe is the executable for Microsoft Lync (now commonly Skype for Business in many organizations). It launches when you sign in to your corporate communications service and handles instant messaging, presence, voice/video calls, screen sharing, and conferencing. The client runs across multiple processes to isolate UI, messaging, and media tasks for stability.
This process uses a multi‑process architecture: a main UI process manages windows and controls, while separate background and media processes handle chat, audio/video streams, and server communication for presence and conferencing.
Quick Fact: Lync evolved into Skype for Business; enterprise deployments still rely on lync.exe for presence, IM, and conferencing features.
Types of Lync Processes
- Client UI Process: Main Lync window, contact list, and chat UI
- Presence/Directory Process: Handles presence updates and directory lookups
- Chat/IM Renderer Process: Renders conversations and message streams
- Voice/Video Engine Process: Manages audio/video capture, encoding, and calls
- Sign-in & Credential Process: Authentication flows and token management
- Background Services Process: Notifications, calendar integration, and status syncing
Is lync.exe Safe?
Yes, lync.exe is safe when it's the legitimate file from Microsoft downloaded as part of Office/Skype for Business from official sources.
Is lync.exe a Virus or Malware?
The real lync.exe is NOT a virus. Malware sometimes uses similar names to trick users.
How to Tell if lync.exe is Legitimate or Malware
- File Location: Must be in
C:\Program Files\Microsoft Office\root\Office16\lync.exe or C:\Program Files (x86)\Microsoft Office\root\Office16\lync.exe. Any other location is suspicious.
- Digital Signature: Right-click the file in Task Manager or Explorer -> Properties -> Digital Signatures. Should show "Microsoft Corporation".
- Resource Usage: Normal usage is 1-15% CPU and 100-400 MB memory during active use. Persistent high usage when idle is suspicious.
- Behavior: Lync should run when you sign in or actively use the client. If it starts on its own or without user interaction, investigate.
Red Flags: If lync.exe is located in unusual folders (Temp, AppData, System32), runs when you are not using Lync, has no valid digital signature, or shows unusual resource patterns continually, scan with antivirus software. Watch for similarly-named files like "lync32.exe" from untrusted sources.
Why Is lync.exe Running on My PC?
lync.exe runs to support presence, messaging, and calls for Microsoft Lync/Skype for Business. It may start at sign-in and continue in the background to handle notifications and ongoing meetings.
Reasons it's running:
- Active Sign-in: You're signed in to Lync/Skype for Business; presence, chat, and calls require running services.
- Background Presence: Presence updates and contact list monitoring occur in background to provide up-to-date status.
- Meeting or Call Scheduling: Conferencing features initiate processes for audio/video streams.
- Office Integration: Outlook/Calendar integration updates meeting invites and presence status.
- Notifications & Sync: Lync keeps background services alive to deliver messages and status changes even when UI is minimized.
Can I Disable or Remove lync.exe?
Yes, you can disable lync.exe. It’s safe to sign out and prevent startup if you no longer need Lync/Skype for Business. Removing the component from Office is possible in some Office configurations.
How to Stop lync.exe
- End Active Sessions: Sign out from Lync and close all conversation windows
- Close UI: Exit Lync from the system tray or File -> Exit
- Prevent Startup: Office/Windows startup settings: disable Lync from starting with Windows
- Disable Background Ops: In Lync options, turn off background presence and notification features if available
- Consider Uninstalling Component: If available, modify Office installation to remove Skype for Business/Lync components
How to Uninstall Lync/Skype for Business
- ✔ Windows Settings → Apps → Apps & Features → Microsoft Office → Modify → Add/Remove Features; uncheck Skype for Business/Lync if present and apply changes
- ✔ Control Panel → Programs → Programs and Features → Microsoft Office → Change → Add/Remove Features; remove Skype for Business/Lync if offered, then follow prompts
- ✔ If not available, you can uninstall the Office suite or use an alternative communications client; consider Teams for corporate chat and meetings
Common Problems: Presence, Chat, or Call Issues
If lync.exe is behaving oddly or not performing as expected:
Common Causes & Solutions
- Outdated Office or Lync version: Update Office to the latest version and ensure Lync/Skype for Business components are up to date
- Sign-in problems: Verify credentials, reauthenticate, and check the organization's sign-in services
- Network or firewall blocks: Ensure the required ports for Lync/Skype for Business are open and that firewall rules permit the client
- Presence not updating: Sign out/in and verify calendar/Outlook integration settings; check service connectivity
- Audio/video quality issues: Check microphone/camera permissions, update drivers, and adjust Lync call quality settings
- Lync crashes on launch: Run Office Repair, reinstall the Lync/Skype for Business component, or perform a clean Office reinstall
Quick Fixes:
1. Sign out from Lync, then sign back in
2. Update Office to the latest version
3. Run Office Repair from Programs and Features
4. Close unnecessary chats and disable high‑bandwidth media in calls
5. Check firewall/NAT settings and ensure required ports are open
Frequently Asked Questions
Is lync.exe a virus?
No, the legitimate lync.exe from Microsoft is not a virus. Ensure the file is located in C:\Program Files\Microsoft Office\root\Office16\lync.exe or C:\Program Files (x86)\Microsoft Office\root\Office16\lync.exe and has a valid signature from Microsoft.
Why is lync.exe using so much CPU?
High CPU can be caused by active video calls, screen sharing, or many concurrent chats. Check the Lync call status, reduce video quality, and close unused chats to reduce load.
Can I disable lync.exe without losing chat history?
Yes. Sign out of Lync and disable startup; you can keep chat history stored in your account data if you use Outlook/Exchange integration, though local caching may be reduced.
Where is lync.exe located on Windows?
Typical locations are C:\Program Files\Microsoft Office\root\Office16\lync.exe or C:\Program Files (x86)\Microsoft Office\root\Office16\lync.exe, depending on Office installation and architecture.
How do I update Lync/Skype for Business?
Update Office through Windows Settings → Update & Security or via Office app → Account → Update Options → Update Now to ensure Lync components are current.
Does Lync still exist in Office 365 environments?
In many organizations Lync has been replaced by Skype for Business or Microsoft Teams. Some deployments still include Lync as part of legacy Office configurations or hybrid setups.