IE 8 Update Message

I have never had to work with IE support until my recent project.

I noticed that most Meteor Websites do not work with IE 8, and I have basically given up supporting it and I wanted to show a little message on top to redirect the user to updating their browser.

I tried to load and noticed that it showed that little message on top. What could I search on google or SO to guide me into achieving this?

PS. English is not my first language. I apologize for the confusion that I may have caused.