Can you quit the Teams application and also ensure that it is not running via the hidden icons (pyramid icon) in the bottom right of the taskbar by right-clicking on the Teams icon, selecting quit?
In the Windows task bar, click on the magnifying glass and type in Control Panel. Ensure the View By is set to Small Icons
Double-click on Programs and Features
Select Microsoft Teams and click Uninstall.
Wait for the application to finish uninstalling. Reboot your computer and logon.
Open a browser to https://www.microsoft.com/en-gb/microsoft-365/microsoft-teams/download-app and download the desktop app.
Once downloaded, (it should appear in the bottom of your browser window), double-click the file to reinstall the application.
Following successful installation of the application, launch Teams and let me know how you get on.