@BobHarris wrote: What does that mean?
If you look at the Windows "taskbar" -- by default, it is positioned on the bottom of the screen, do you see more than one icon for your web-browser, or overlapping icons? If so, right-mouse-button click on one icon, and choose "close". Repeat for each other instance.
Note the overlapping icons for Microsoft Edge. That indicates that you have multiple instances.