Method 1: Disable from Task Manager

You can disable Microsoft Teams from Task Manager and it will not start up automatically:

1. Press Ctrl + Shift + Esc key to open Task Manager.

2. Go to Startup tab.

3. Click on Microsoft Teams, and click on Disable.

Method 2: Change settings

You can change the settings in Microsoft Teams and see if that helps:

1. Launch Microsoft Teams.

2. Click on the Profile icon on the top right corner and click on Settings.

3. Scroll down and clear the checkbox for Auto Start Application.