If Microsoft Teams keeps reinstalling itself on your Windows PC and running itself on boot up, there is a solution. Microsoft Teams cannot be uninstalled the normal way: it must be uninstalled twice.
It’s silly, but that’s how it works. Specifically, you will have to uninstall both the “Microsoft Teams” and the “Teams Machine-Wide Installer”. If you have just uninstalled the Microsoft Teams app, the device-wide installer will reinstall it every time you sign in to your PC. To completely uninstall Teams, you must remove both apps.
On Windows 10, go to Settings > Apps > Apps & Features to delete both.
Under Apps & Features, find “Teams”. Remove Microsoft Teams as well as the Teams Machine-Wide Installer.
You can also use the classic Control Panel to uninstall these apps. Head to Control Panel > Programs > Uninstall a Program, search for “Teams”, and Remove Microsoft Teams as well as the Teams Machine-Wide Installer.
you are done! The next time you sign in to your computer, Teams won’t automatically reinstall itself. It will remain deleted from your system until you intentionally download and install it.
Teams will be uninstalled as well if you delete Office, according to the Microsoft website. In many circumstances, Microsoft Office seems to instal both Teams and the Teams Machine-Wide Installer automatically.