Closing TeamViewer completely on Windows requires ending background processes:
1. Open Task Manager
Press Ctrl + Shift + Esc or right-click the Taskbar and choose Task Manager.
2. Find TeamViewer Entries
Under Processes, look for:
TeamViewer.exe
TeamViewer_Service.exe (or similar)
3. End Each Task
Right-click on each TeamViewer entry → End Task
4. (Optional) Disable Auto-Start
To prevent it from auto-starting in the future, or if it keeps restarting when you End Task:
Within TeamViewer:
Go to Extras → Options → General
Uncheck “Start TeamViewer with Windows”